Annual climate statement 2019
Australia’s climate in 2019
- Australia's warmest year on record, with the annual national mean temperature 1.52 °C above average
- Both mean annual maximum and minimum temperatures above average for all States and the Northern Territory
- Annual national mean maximum temperature warmest on record (2.09 °C above average)
- Widespread warmth throughout the year; January, February, March, April, July, October, and December all amongst the ten warmest on record for Australian mean temperature for their respective months
- Significant heatwaves in January and in December
- Australia's driest year on record
- Nationally-averaged rainfall 40% below average for the year at 277.6 mm
- Rainfall below average for most of Australia
- Rainfall above average for parts of Queensland's northwest and northern tropics
- Much of Australia affected by drought, which was especially severe in New South Wales and southern Queensland
- Widespread severe fire weather throughout the year; national annual accumulated Forest Fire Danger Index highest since 1950, when national records began
- One of the strongest positive Indian Ocean Dipole events on record; El Niño–Southern Oscillation neutral throughout the year
Australia's warmest year on record; marked by severe, protracted drought
2019 was Australia's warmest year on record. Australia's area-averaged mean temperature for 2019 was 1.52 °C above the 1961–1990 average, well above the old record: +1.33 °C in 2013. Mean maximum temperatures were the warmest on record at 2.09 °C above average, also well above the previous record, which was +1.59 °C in 2013. Mean minimum temperatures were 0.95 °C above average, the sixth-warmest on record. The national temperature dataset commences in 1910.
The mean temperature for the 10 years from 2010 to 2019 was the highest on record, at 0.86 °C above average, and 0.31 °C warmer than the 10 years 2000–2009. All the years since 2013 have been amongst the ten warmest on record for Australia. Of the ten warmest years, only one (1998) occurred before 2005. Warming associated with anthropogenic climate change has seen Australian annual mean temperatures increase by over one degree since 1910. Most of this warming has occurred since 1950.
2019 was also the driest year on record for Australia at 277.6 mm, well below the previous record in 1902 (previous lowest was 314.5 mm). Nationally-averaged rainfall for 2019 was 40% below the 1961–1990 average of 465.2 mm. The national rainfall dataset commences in 1900. Although every period of rainfall deficiency is different, the extraordinarily low rainfall experienced this year has been comparable to that seen in the driest periods in Australia's recorded history, including the Federation Drought and the Millenium Drought.
A very strong positive Indian Ocean Dipole (IOD) was one of the main influences on Australia's climate during 2019, and contributed to very low rainfall across Australia. The year commenced with significant rainfall deficiencies already in place across large areas of eastern Australia. Low rainfall during 2019 resulted in increased severity of rainfall deficiencies across New South Wales and Queensland, parts of southeastern Australia, and the South West Land Division in Western Australia.
The El Niño–Southern Oscillation remained neutral throughout 2019.
Annual mean temperatures for 2019 were above average for nearly all of Australia, and highest on record for a large area of northern and eastern New South Wales, southeast Queensland, most of Western Australia extending from the Pilbara coast to northwest South Australia, and for an area of the Victoria River District in the Northern Territory. It was the warmest year on record for New South Wales and Western Australia as a whole, and amongst the ten warmest years for the Northern Territory, Queensland, Victoria, and South Australia.
Rainfall for the year was below to very much below average over most of Australia. Much of northeastern New South Wales and southeastern Queensland, pastoral South Australia, the central and southern Northern Territory, and southeastern Western Australia received their lowest annual totals on record. Annual rainfall was above average across parts of Queensland's northwest and northern tropics, mostly as a result of very much above average rainfall during the first quarter of the year.
The second half of the year was particularly dry across most of the southern half of Australia, and followed several years of below average rainfall over parts of Queensland and New South Wales. Warm and windy conditions during spring to early summer led to repeated periods of severe fire weather, with very large bushfires affecting eastern Australia from September, with many fires continuing to burn after the end of the year.
All capital cities were warmer and drier than average in 2019.
Daytime temperatures were especially warm, with Sydney, Canberra, Brisbane, and Hobart all observing their highest annual mean maximum temperature on record. Perth was equal-warmest and Darwin the second-warmest. While not in the top ten, Melbourne also had warmer than average days.
All of the capital cites, except Darwin and Perth, observed warmer than average annual mean minimum temperatures, though none set a new record. For Darwin and Perth the annual mean minimum temperature was close to average.
Brisbane and Canberra had their highest annual mean temperature on record, and all other capital cities were warmer than average overall. Hobart and Sydney had their second-warmest annual mean temperature.
Rainfall was below average in all the capital cities. Each city, except Sydney, had rainfall totals in the driest 10% of years. Sydney had many months with below-average rainfall, but also some wet months; its annual total rainfall was in the driest 15% of years. Darwin had its seventh-driest wet season over 2018–19, and a late start to the 2019–20 wet season.
Table of annual rainfall, temperature and sea surface temperatureTable of annual national rainfall, temperature, and sea surface temperature anomalies and ranks
Globally, 2019 likely to be the second-warmest year on record
The global mean temperature for January to November 2019 was 0.81 ± 0.1 °C above the 1961–1990 average. This means 2019 is on track to become the second-warmest year on record for global mean temperatures since 1880.
Even though 2019 was not as warm as the record set in 2016, the five warmest years on record are the most recent five years. The notable warmth of 2017, 2018, and 2019 occurred without the presence of El Niño (which typically boosts global temperatures). All of the ten warmest years on record have occurred between 2005 and the present, with El Niño contributing in four of these years. The warmest year on record was 2016, 0.87 ± 0.1 °C above the 1961–1990 average.
Global mean temperatures were above average throughout 2019, with all months to November amongst the four warmest on record for their respective months.
Global temperatures have increased by approximately 1.1 °C since around the year 1750, and since 1978 no year has observed a global mean temperature below the 1961–1990 average.
Based on preliminary data for January–November 2019, temperatures were warmer than the 1961–1990 average across most of the world's land and oceans, and unusually warm over large areas of the Arctic, including Alaska and central northern Russia. Large areas of the western Indian Ocean were also much warmer than average. In contrast, the mean temperature was cooler than average over a large area of North America.
The very strong positive Indian Ocean Dipole (IOD) led to a delayed onset and a delayed withdrawal of the Indian Monsoon, resulting in large precipitation deficits over the Indian subcontinent during June, but above average rainfall in later months. The positive IOD was also associated with drought in parts of southeast Asia and the southwest Pacific. Drought in Indonesia was associated with the most significant fire season since 2015. Parts of east Africa which had previously been affected by drought saw flooding associated with the positive IOD during October and November.
There was significant drought in many parts of southern Africa during the 2018–19 wet season, and parts of Central America also experienced substantially below average rainfall during the first nine months of the year.
There was major flooding in parts of South America during January, and in Iran during late March and early April, and in the Indian subcontinent at various times during the monsoon season. Destructive cyclones caused significant impacts in many places, including east Africa in March (Idai), the Bahamas in September (Dorian), and Japan in October (Hagibis).
Major heatwaves affected northern and western Europe in late June and late July, extending into the Nordic countries later. The Arctic was also unusually warm during 2019, with above average fire activity.
About the global temperature estimate
The global mean temperature is estimated using observational datasets from the UK Met Office Hadley Centre (HadCRUT4), the US National Oceanic and Atmospheric Administration (NOAAGlobalTemp), the US Goddard Institute of Space Studies (GISTEMP v4); and reanalysis datasets from the European Centre for Medium-Range Weather Forecasts (ERA5) and the Japan Meteorological Agency (JRA-55).
Temperature values from the observational datasets commence in 1880 for NOAAGlobalTemp and GISTEMP and in 1850 for HadCRUT4, while the two reanalysis datasets commence in 1958 for JRA and 1979 for ERA.
Australia's warmest year on record; exceedingly warm maximum temperatures
2019 was Australia's warmest year on record, with the annual national mean temperature 1.52 °C above average, surpassing the previous record of +1.33 °C in 2013.
Warmth was widespread and persistent throughout 2019 — January, February, March, April, July, October, November, and December were all amongst the ten warmest on record for Australian mean temperature for their respective months. January, March, and December were the warmest on record, with January and December exceeding their previous records by a substantial 0.98 °C and 1.08 °C respectively.
Annual mean temperatures were above average for nearly all of Australia. They were the highest on record for much of Western Australia away from the coast, extending into northwest South Australia and the southwest of the Northern Territory, northern and eastern New South Wales, and southeastern Queensland, and an area of the Victoria River District in the Northern Territory. The annual mean temperature was in the highest 10% of historical observations for most of the rest of Australia, except northern to central western Queensland. It was amongst the ten warmest years on record for all mainland States and the Northern Territory.
Maximum temperatures for the year were also well above average across all of Australia. They were the highest on record for nearly all of Western Australia; most of South Australia, away from the northeast and parts of the southeast; most of the western half of the Northern Territory; eastern New South Wales; southeastern Queensland; and Gippsland in Victoria and part of east coast Tasmania. The annual mean maximum temperature was in the highest 10% of historical observations for most of the rest of Australia, except northern to central western Queensland where it was nevertheless also above average. Annual mean maximum temperatures were amongst the ten warmest on record for all mainland States and the Northern Territory.
Annual mean minimum temperatures were also above average for much of the country, but close to average in areas of the northern tropics; an area of the southeastern Northern Territory and western Queensland; and some areas of the south of Western Australia and South Australia. Annual mean minima were in the highest 10% of historical observations for large parts of inland and northwestern Western Australia; western South Australia; parts of the central Northern Territory and Queensland's Gulf Country; southern Queensland and much of New South Wales; and parts of central to eastern Victoria. Annual mean minimum temperatures were amongst the ten warmest on record for New South Wales, Victoria, Western Australia, and the Northern Territory.
An extended period of heatwaves over much of Australia began in early December 2018 and continued into January 2019. The delayed northern Australian monsoon saw heat build over the north, which persisted through much of summer. January was an exceptional month: Australia's warmest month on record for any time of the year, with the monthly mean temperature 2.90 °C above average. It was the warmest January on record for New South Wales, Queensland, Victoria, Tasmania, and the Northern Territory.
Severe intensity heatwave conditions extend across southern Australia at times during January.
February was also much warmer than average across western and far northern Australia, and for much of southern Queensland and northern New South Wales.
In total, summer 2018–19 was the warmest on record for Australia. The widespread warm and dry conditions, on top of well below average rainfall over multiple months, contributed to elevated fire danger over much of southeastern Australia during summer. Large fires affected Gippsland in Victoria and parts of Tasmania from summer into autumn, burning large swathes of remote and wilderness regions.
Unusual warmth persisted across March and April. Much of Australia was very much warmer than average for March, including areas of highest on record mean temperature in Western Australia, the western Northern Territory, and southeast Queensland and northeast New South Wales. Large areas were also very much warmer than average for April.
May days remained warmer than average for the northwest and coastal southeast, and while nights were warmer than average across the north. Mean minimum temperatures were cooler than average over the southern half of Western Australia, with some stations having for their coldest May night on record around the middle of the month.
Mean maximum temperatures were generally remained warmer than average for most of Australia for June to August, with July an exceptionally warm month. Mean maximum temperatures for the month were highest on record for July over large areas of northwestern Australia, and also for parts of eastern New South Wales and adjacent southern Queensland.
In the southeast and Central Australia clear skies and sunny days during August meant much cooler than average nights, with areas of the inland southeast observing their coolest mean minimum temperatures on record for the month. Minima were also below to very much below average for areas of the mainland southeast and tropical Australia for September. Frosts caused crop damage to some grain-growing regions in southern Australia. Nights were also cooler than average for parts of the far north during October, and northern Australia, Central Australia, South Australia, and western Victoria for November.
The reduced cloud cover, low humidity, and low soil moisture seen during 2019 are typical of eastern inland Australia during the cool season in drought years. This leads to an increase in frosts but also days with a large diurnal temperature range (the difference between daily maximum and minimum temperatures). Drier soils also lead to reduced evaporation from the landscape, which would otherwise exert a buffering effect on temperatures, contributing to both higher daytime temperatures and cooler nights.
Mean maximum temperatures were above to very much above average for most of Australia from September through December. They were warmest on record for much of southern Western Australia during September, northern Western Australia during October, and for very large parts of the mainland during December.
Spring was the fifth-warmest on record for Australia as a whole, and was also Australia's driest spring on record. Coming on the back of long-term rainfall deficiencies which had already led to a drying of the landscape, and in conjunction with the very warm temperatures, dangerous fire weather resulted across much of eastern and southern Australia. See Special Climate Statement Severe fire weather conditions in southeast Queensland and northeast New South Wales in September 2019.
December brought an exceptionally warm end to the year, with the month the warmest December on record for Australia, and amongst the ten warmest Decembers on record for the Northern Territory and all States except Tasmania. A slow-moving high pressure system over the Great Australian Bight brought a record-breaking heatwave from the middle of the month, affecting large areas as a mass of hot air circulated over the country during the second half of the month. The warmth was widespread, affecting nearly all of Australia at some point. A large number of daily high temperature records for December, including some records for any month of the year. Records were set in all States and the Northern Territory, but were most numerous in South Australia, Victoria, New South Wales, and Tasmania. On two consecutive days, the 17th and 18th, records were set for Australia's hottest day on record. The national area-averaged maximum temperature on the 18th was 41.9 °C, a whole degree above the value for the 17th (40.9 °C). Both of these values exceed the previous record of 40.30 °C set on 7 January 2013.
Heat continued to affect Australia until the end of the year, bringing repeated periods of severe fire weather to the southeastern States.
The frequency of extreme heat events has increased approximately fivefold since the 1950s. Research by the Bureau shows that climate change has contributed to an increased frequency and severity of extreme heat, heatwaves and elevated fire danger.
New records for high daily Forest Fire Danger Index (FFDI) values were set in some areas of all States and Territories (FFDI is one common measure of fire weather conditions) during spring, Almost all of Australia had spring accumulated FFDI values that were very much above average (highest 10% of years), including almost 60% of the country that was highest on record. Significant bushfires started in southeastern Queensland and northeastern New South Wales in early September. Spring brought little rainfall over the fire grounds, and further fires started across eastern New South Wales, and also in eastern Victoria and on South Australia's Eyre Peninsula. Recurrent periods of high temperatures and windy weather saw little reprieve. More details on dangerous bushfire weather and heat in spring 2019 can be found in the related Special Climate Statement.
Additional fires started as spring progressed, with significant fires across much of eastern New South Wales, including on the outskirts of Sydney, in East Gippsland in Victoria, in the Alpine region, and in southeast South Australia.
In the absence of widespread rainfall, the fires continued to burn across a large area of eastern Australia at the end of the year, spread from southeast Queensland, through eastern New South Wales, and in northeastern Victoria and Gippsland. The period around New Year's saw particularly hazardous fire weather, with further significant fires igniting while existing fires experienced renewed flares.
Areal average temperatures
|Areal average temperatures|
|Maximum Temperature||Minimum Temperature||Mean Temperature|
|Australia||110||+2.09||highest (was +1.59 °C in 2013)||105||+0.95||6th highest||110||+1.52||highest (was +1.33 °C in 2013)|
|Queensland||106||+1.46||5th highest||99||+1.09||105||+1.27||6th highest|
|New South Wales||110||+2.44||highest (was +2.13 °C in 2018)||110||+1.45||highest (was +1.40 °C in 2016)||110||+1.95||highest (was +1.68 °C in 2018)|
|Victoria||107||+1.37||4th highest (record +1.44 °C in 2018)||102||+0.72||9th highest||106||+1.05||5th highest|
|Tasmania||= 98||+0.64||84||+0.17||= 93||+0.41|
|South Australia||110||+2.30||highest (was +2.02 °C in 2013)||= 92||+0.59||109||+1.45||2nd highest (record +1.64 °C in 2013)|
|Western Australia||110||+2.50||highest (was +1.36 °C in 2014)||108||+0.83||3rd highest (record +1.30 °C in 1998)||110||+1.67||highest (was +1.09 °C in 2013)|
|Northern Territory||110||+1.96||highest (was +1.70 °C in 2013)||104||+1.02||7th highest||109||+1.49||2nd highest (record +1.50 °C in 2013)|
Australia's driest year on record, with drought affecting large areas
Annual rainfall in 2019 was very much below average over much of Australia, although parts of Queensland's northwest and northern tropics were wetter than average.
The national total rainfall for 2019 was 40% below the 1961–1990 average at 277.6 mm (the 1961–1990 average is 465.2 mm). This makes 2019 the driest year in the 119 years since 1900.
Rainfall for the year was below average for southern Queensland, across the Central Highlands and Central Coast districts, and parts of the Gulf coast. It was also below average for New South Wales; Victoria; most of Tasmania except the west; South Australia; and nearly all of Western Australia and the Northern Territory. Annual rainfall totals were in the lowest 10% of historical observations for almost 70% of Australia, encompassing most of New South Wales and the southeastern quarter of Queensland; large areas of northwestern, northeastern, and eastern Victoria; eastern Tasmania; most of South Australia; most of the Northern Territory except some eastern regions; and much of Western Australia except some parts of the Kimberley, northwest, Gascoyne, and Goldfields.
Annual rainfall was above average for some areas of Queensland in the northwest, on the northern coast around Townsville, and on the tip of Cape York Peninsula. Rainfall was also above average for a small area of the Pilbara coast in Western Australia. In both States above average annual totals resulted from tropical systems which caused flooding in the first quarter of the year.
Despite January being drier than average for much of the country, tropical activity late in the month resulted in above average monthly rainfall for much of Queensland's central and northern coasts, as well as the eastern Top End in the Northern Territory. Heavy rainfall continued into early February, with above average monthly totals across northern Queensland. Large areas of flooding resulted in coastal tropical Queensland, including around Townsville, and parts of the western Peninsula and Gulf Country (see Special Climate Statement An extended period of heavy rainfall and flooding in tropical Queensland and report on tropical low 13U).
Flooding continued in western Queensland into April, boosted by above average monthly rainfall for large areas in March, partly as a result of severe tropical cyclone Trevor, which crossed the Peninsula during the second half of the month. In the low-lying regions of western Queensland, floodwaters spilled from the Flinders River into neighbouring catchments. Flooding in the region was the most significant for at least 50 years, and resulted in great stock losses and damage to property. Floodwaters from the north eventually reached Lake Eyre / Kati Thanda, with inflows beginning in mid-March and continuing into winter, bringing the most significant filling of the Lake since 2010–11.
In the west, severe tropical cyclone Veronica caused major flooding in the coastal Pilbara during March. Veronica was slow moving very close to the coast for a number of days, confining rainfall to a small area. Rainfall totals reached more than four times the March monthly average, equivalent to more than an average year's worth of rainfall.
April rainfall was above average for parts of the Gascoyne in Western Australia, the Top End, inland Queensland and northwestern New South Wales; for the southeastern mainland the month was much drier than average.
Outside of Queensland, the northern wet season (October 2018–April 2019) was drier than average for the Northern Territory and Western Australia. The monsoon arrived later than usual during the 2018–19 wet season, with onset at Darwin not occurring until 23 January 2019, the equal third-latest since reliable records commenced in 1957. The very strong positive IOD during 2019 has contributed to another late start to the northern wet season in 2019–20, with no monsoonal activity seen across northern Australia before the end of 2019.
Unusually late tropical activity in May contributed to above average rainfall for the far northern tropics, extending across the Northern Territory into Central Australia. This included two late-season tropical cyclones; Lili, affecting the Top End, and Ann, which crossed Queensland's Cape York Peninsula.
May was much drier than average for most of Western Australia and much of east coast Australia.
Rainfall was generally below average over large areas of the country for the remainder of the year, and particularly low over mainland southern Australia from July onwards. Nationally, each month from July through December was amongst the ten driest on record for their respective month. For the period as a whole July–December rainfall was the lowest on record for the southern half of Australia.
The end of the year was especially dry, with November and December the driest on record for their respective months nationally.
Rainfall deficiencies and water storagesThe year commenced with significant rainfall deficiencies already in place across large areas of eastern Australia, and the exceptionally low rainfall throughout 2019 resulted in an increase in the severity and spatial extent of these rainfall deficiencies during the year (see Special Climate Statement Drought conditions in eastern Australia and impact on water resources in the Murray–Darling Basin).
On 2- to 3-year timescales, starting in early 2017, rainfall has been near or below previous record low values over much of New South Wales and southern Queensland, in many regions comparable to records set in 1900–1902 during the Federation Drought. The impact of low rainfall over the period has been exacerbated by record high temperatures, which in turn drive higher rates of evaporation where water is available.
Low rainfall also led to very low soil moisture across large areas of Australia during 2019, particularly across the Murray–Darling Basin. The average annual soil moisture in 2019 was the lowest on record in five of the 26 river catchments of the Basin, and for the Basin as a whole was the third-lowest on record (behind 2018 and 2002). October saw particularly low root-zone soil moisture (from 0 to 100 cm deep) in the Basin, with six catchments observing record low soil moisture for the month.
Dry soils also limit surface runoff, because water is absorbed into the soil. Winter to spring is traditionally a filling period for water storages across southern and southeastern Australia. The 'filling' season has been below average for the past three years in the Murray–Darling Basin, and runoff in 2019 was the second-lowest on record behind 2006. With low streamflows and limited runoff, there were only marginal increases to storages across the Southern Basin during the year and no meaningful inflows in the Northern Basin where storages remained extremely low or close to empty. By the end of 2019 water storage in the Northern Murray–Darling Basin had dropped to less than 7% of capacity. Storage levels in the Northern Basin at the end of 2019 were lower than at any point during the Millennium Drought (2001–2009). In the Southern Basin total storage volume in 2019 went from 53% in January down to 39% at the end of the irrigation season in April. The storages had reached 47% by the end of the filling season, and decreased again as spring progressed into summer.
While the effect of the protracted period of below average rainfall was severe across the Murray–Darling Basin, serious rainfall deficiencies on annual to multi-year timescales also affected coastal New South Wales; eastern Victoria; eastern South Australia, extending into far northwestern Victoria; east coast and north coast Tasmania; and much of the South West Land Division in Western Australia.
Eleven tropical cyclones were recorded in the broader Australian region during the 2018–19 tropical cyclone season, equalling the long-term average (for all years since 1969–70). Six tropical cyclones reached severe (category 3), the first time since the 2014–15 season.
Three of the eleven tropical cyclones crossed the coast (Owen, Penny, and Trevor). Veronica did not cross the coast as a tropical cyclone, but did sit just off the Pilbara coast for around 48 hours. Severe tropical cyclone Veronica caused major flooding in the Pilbara, resulting in extensive disruption to shipping and onshore industry, while Trevor set daily rainfall record for March in some parts of northern Queensland, and displaced people from a number of remote communities along the western Gulf coast.
As of 31 December 2019, the 2019–20 tropical cyclone season was yet to see any tropical cyclones.
The tropical cyclone season typically runs from 1 November to 30 April, although tropical cyclones can and do form outside of those bounds (for instance, both Lili and Ann were active during May 2019). All tropical cyclones existing between 1 July and 30 June the following year count towards the season total. The broader Australian region covers the area south of the Equator and between 90°E and 160°E, and includes Australian, Papua New Guinea, and Indonesian areas of responsibility.
|New South Wales||1||250.2||−55%||lowest|
|Victoria||10||473.1||−28%||10th lowest; lowest since 2006|
|Western Australia||2||173.7||−49%||2nd lowest (record 168.0 mm in 1924)|
|Northern Territory||2||268.1||−50%||2nd lowest (record 241.4 mm in 1961)|
Major climate influences during 2019: long-lived, very strong positive Indian Ocean Dipole
Persistent warmth during 2019 was driven by a combination of the long-term warming trend and natural climate drivers including a very strong and long-lived positive Indian Ocean Dipole (IOD).
The pattern of sea surface temperatures in the Indian Ocean was generally consistent with a positive IOD from late May, and firmly in positive territory between August and the end of the year. During spring the IOD index reached the highest weekly values observed in the Bureau's dataset, which extends from 2001. The index peaked at +2.15 °C for the week ending 13 October, well above the previous record of +1.48 °C for the week ending 5 November 2006. Values remained above the previous record from mid-September to mid-November. Values from NOAA's monthly IOD dataset suggest the 2019 event was amongst the strongest on record, comparable to the very strong events of 1961, 1994, and 1997.
Typically, IOD events break down in late spring or early summer as the monsoon trough moves into the southern hemisphere, which changes broadscale wind patterns over the IOD region, and returns sea surface temperatures to near average. However, the retreat of the Southwest Indian Monsoon was very slow during 2019, six weeks later than average and the latest on record. The transition of the monsoon trough into the southern hemisphere was very late, and the positive IOD persisted beyond the end of 2019.
The IOD was also positive in 2018, and while not meeting criteria for a positive IOD in 2017, the general pattern of sea surface temperatures in the Indian Ocean during that year was also unfavourable for rainfall across Australia. This has been a significant contributor to the prolonged period of below average rainfall across much of Australia during the past three years, and the exceptional warmth of 2019.
It is unusual but not unprecedented to have successive positive IOD events. While the IOD is a natural mode of variability, its behaviour is changing in response to climate change. Research suggests that the frequency of positive IOD events, and particularly the occurrence of consecutive events, will increase as global temperatures rise.
The other main driver of natural climate variability in Australia, the El Niño–Southern Oscillation (ENSO), remained neutral throughout 2019.
A sudden stratospheric warming (SSW), when the stratosphere high above the South Pole rapidly heated, began at the end of August, and was the strongest SSW event since 2002. This induced a negative phase of the Southern Annular Mode (SAM) from late October to late December, shifting the belt of westerly winds over the Southern Ocean northwards towards the equator.
The temperature and rainfall patterns of spring and early summer 2019 were consistent with the negative SAM, which is associated with a reduction in rainfall over parts of eastern Australia owing to decreased onshore flow, but wetter conditions for western Tasmania and other areas of the southern coast which are exposed to the enhanced westerly winds. Negative SAM is also associated warmer than average spring temperatures and an increased chance of spring heatwaves across southern and eastern Australia.
In addition to the influence of natural drivers, Australia's climate is increasingly affected by global warming and natural variability takes place on top of this background trend. Australia has warmed by over one degree since 1910, with most of the warming occurring since 1950. The ocean waters around Australia have also warmed significantly over the past century, and have been very warm consistently across the past two decades. The background warming trend can only be explained by human influence on the global climate. The role of climate change is further discussed in State of the Climate 2018.
There has been a significant decline in autumn and winter rainfall observed over southeast and southwest Australia including in higher rainfall parts of the Murray–Darling Basin in recent decades. The drying trend is particularly strong for May–July over southwest Western Australia since 1970, and for April–October over the southeast of the continent since 1999.
A major influence on this drying has been the strengthening and extension of the subtropical high pressure ridge during winter, shifting many potential rain-bearing weather systems south of the Australian continent. This southwards shift of frontal systems is an expected outcome of climate change. However during 2019, the negative SAM between October and December somewhat countered this trend over west-facing southern Victoria and much of Tasmania.
Conversely to the drying trend in the south, there has been an observed increase in rainfall over parts of northern Australia since the 1970s. This trend towards wetter years in the north is contributing to a slight increase in mean annual rainfall for Australia as a whole.
Sea surface temperatures warmer than average for the Australian region as a whole
The annual 2019 sea surface temperature (SST) anomaly for the Australian region was the equal-20th-highest on record; 0.32 °C above the 1961–1990 average based on data from the NOAA Extended Reconstructed Sea Surface Temperature dataset, ERSST v5. SSTs around Australia have warmed by around one degree since 1910, similar to the increase in temperature observed over land. Above average annual SSTs have been observed for the Australian region for every year since 1995, and have been persistently high for the past decade.
Sea surface temperatures were very much warmer than average across waters to the east of Australia from southeast Queensland to the Tasman Sea and eastern Bass Strait during 2019. For the Tasman Sea region as a whole, mean SSTs were the third-warmest on record (+0.86 °C for 2019, behind +0.96 °C in 2016, and +0.87 °C in 2018). Further afield, SSTs were warmest on record for large areas around New Zealand.
SSTs were also warmer than average across the eastern half of the Great Australian Bight and close to the coast around the remainder of the Bight, for waters adjacent to southeast to central coast Queensland, and offshore of northwestern Australia. SSTs were near average to the southwest of Australia, including the west and southwest coasts of Western Australia. SSTs were near average around the Northern Territory and Queensland's Cape York Peninsula.
SSTs were above average to highest on record for large areas of the broader Australian region in the west of the Indian Ocean and the western Pacific Ocean.
SSTs were in the highest 10% of historical observations for large areas around southeastern Australia and across the Tasman Sea throughout the year. For the Tasman Sea region monthly SSTs were amongst the three warmest on record for each month from January to July, and the fifth-warmest on record for August.
Waters were warmer than average in parts of the Maritime Continent and western Indian Ocean during the first part of the year, although the effect of tropical activity could be seen in cooler than average waters in the Gulf for February. From June SSTs were cooler than average in a large area to the north of Australia, associated with the developing positive IOD. Very much cooler than average monthly mean SSTs were seen to the south of the Indonesian island of Sumatra in October and November, when the event was at its strongest, with some areas coolest on record for their respective months. SSTs were more than two degrees cooler than average in some areas close to Sumatra during October.
For the globe as a whole, the average annual sea surface temperature for 2019 was 0.64 °C above the 1961–90 average, the warmest on record in the ERSST v5 dataset which commences in 1854. The previous warmest year on record was 2016 (+0.62 °C), and eight of the last ten years have been amongst the ten warmest on record.
Global ocean heat content in the upper 700 m and upper 2000 m) has been at or near record high levels during 2019, with the average for the year so far exceeding the previous record highs set in 2018 (see World Meteorological Organization Provisional statement on the State of the Global Climate in 2019).
Please note this list is not exhaustive—for a more complete summary of individual events, including those affecting smaller geographical regions or causing limited damage, please consult the Monthly Weather Review.
An extended warm period with multiple heatwaves over much of Australia began in early December 2018 and continued into January 2019.
A persistence of stable and sunny conditions over much of the country combined with a delayed onset of the Australian monsoon over northern Australia to create ideal conditions for heat build-up. This dome of hot air over the continent brought extreme heat to many areas as weather systems, particularly troughs, introduced hot air into different regions, with little penetration of cooler air from the south to disrupt the hot continental air mass.
Numerous sites set records for runs of consecutive days at or above 40 °C while many other sites reported their highest daily maximum or minimum temperature on record for January, or for any month. More details can be found in the Special Climate Statement Widespread heatwaves during December 2018 and January 2019.
Impacts on the wider community, including power infrastructure, agriculture and human wellbeing, stretched resources of utilities, health agencies, and emergency services. There were also reports of significant impacts on wildlife due to heat stress.
Thunderstorms associated with a fast-moving cold front and low pressure trough produced heavy rain and damaging winds across eastern and central Victoria on 30 January. Glencairn in the Gippsland high country recorded 38 mm of rain in one hour and Mount Wombat, near Euroa, recorded 26 mm in half an hour. The SES reported more than 800 calls for assistance, mostly due to wind damage.
Lightning strikes onto dry vegetation led to bushfires during January, including over 60 that started on the 15th, many in remote and difficult terrain. The Gell River fire in southwest Tasmania, which had started on 27 December 2018, continued to burn. The fires threatened communities in several parts of Tasmania, with the Tasmanian Fire Service issuing Emergency Warnings on many occasions.
Repeated warm days, little or no rain, and some periods of strong winds made the fires difficult to control. Intensive and sustained efforts by several hundred fire fighters, augmented by aircraft, ensured that building losses were limited, although large tracts of wilderness and forests were burnt in the southwest, Huon Valley, and Central Plateau. The total area burnt by the end of January was estimated at over 178 000 hectares, or about 2.6% of Tasmania. The area burnt in the 2018–19 season was the second largest on record for Tasmania, and the largest since at least 1967. For further details see Significant Weather section of the January Monthly Weather Review.
Southern Tasmania experienced poor air quality from mid-January to early February, including at locations well removed from the actual fires, while smoke from northwestern Tasmania also reached Victoria in the first week of February.
Extreme temperatures and sudden changes in wind direction and strength produced conditions conducive to bushfires across eastern Victoria in early January.
On the 4th, strong and hot northerly winds saw around 200 fires across Victoria, including a large fire near Rosedale in Gippsland that burnt more than 550 hectares. The SES responded to over 100 reports of fallen trees and 22 incidents involving damage to buildings, mainly in Melbourne and surrounding areas.
A complex fire in the Thomson catchment, just north of Mount Baw Baw, had burnt through about 4770 hectares by 1 February. A bushfire 10 km north of Timbarra, in East Gippsland, began around the 16th. The fire was under control by the 26th and had burnt through over 13 000 hectares by the end of January though was still burning into February.
An active monsoon trough and a slow-moving low pressure system produced extremely heavy rainfall in tropical Queensland from late January into early February, causing flooding on Queensland's tropical coast between Daintree and Mackay, and parts of the western Peninsula and Gulf coast. Full details can be found in Special Climate Statement An extended period of heavy rainfall and flooding in tropical Queensland and report on tropical low 13U.
Heavy rain began on 26 January in areas of the North Tropical Coast and Tablelands, and the Herbert and Lower Burdekin districts, and continued into early February. Over the following days, heavy falls had spread further south to the Central Coast and Whitsundays and inland across the northwestern regions of Queensland.
Major flooding occurred in coastal communities between Daintree and Mackay, including flooding in the Burdekin, Ross, Bohle, Haughton, Herbert, and Black rivers, and Bluewater Creek. Flash flooding and swift water rescues occurred around Black River and Bluewater Creek to the northwest of Townsville, with rainfall totals of more than 200 mm in three hours.
Flooding was extensive and long-lived in the Gulf Country, with major flooding at Walkers Bend on the Flinders River by 2 February. Floodwaters in the Flinders River spilled into neighbouring catchments and spread across an area some 70 km wide and estimated to be at least 1.5&nbp;million hectares in total. Major flooding occurred in a number of Gulf rivers, including the Cloncurry, Leichardt, Flinders, and Norman rivers, with resulting damage to communities, infrastructure, and extensive stock losses.
A gust front associated with a line of thunderstorms developed over western parts of Victoria on 6 February. Winds in excess of 70 km/h resulted in dust storms in Birchip, Kerang, Swan Hill, and Wycheproof. The SES received more than 200 calls for help, mostly for fallen trees and powerlines, and building damage.
There were other dust storms during February, the most notable of which was on the 12th when dust stretched around 1500 km from southwestern Queensland into southeastern Australia, affecting northern Victoria, Canberra, and crossing New South Wales before extending well offshore from the central coast as the associated trough and frontal system tracked out to sea.
Thunderstorms across Victoria during the evening of 6 February led to more than 200 requests for assistance from the SES, mostly relating to building damage around Bendigo and Ararat. Power outages affected around 13 000 premises in the west and central regions of the State, and the northern suburbs of Melbourne. Large hail up to 3 cm was reported in northern suburbs and the metropolitan area.
Tropical cyclone Oma formed near Vanuatu on 12 February and tracked southwest towards the southern Coral Sea late in February, strengthened to briefly reach category 3 strength (severe), before weakening, eventually falling below cyclone intensity on the 23rd. Although Oma remained well offshore, the system caused gale force winds, king tides, coastal erosion, and inundation of low-lying areas in coastal southeast Queensland and contributed to damaging surf which produced coastal erosion in New South Wales. More details can be found in the report on tropical cyclone Oma.
A number of significant new fires commenced during February, in addition to fires still burning from earlier ignitions.
In New South Wales there were two significant fires in the northeast of the State: at Tingha, and at Tabulam, west of Casino.
There was a fire during the second half of February in South West Western Australia, in the shires of Donnybrook–Balingup and Nannup.
Several significant fires which had started during January in Victoria in Gippsland and near Mount Baw Baw continued to burn throughout the month, while a fire started near Walhalla in late February.
In Tasmania, fires which had been burning since late December or mid-January remained alight, but contained, in inaccessible terrain. Warm and very windy conditions on 27 February, in addition to dry vegetation and soil, saw bush fires flare near Tea Tree, Cygnet, Judbury, Ouse, and Campania.
With little rain during March, most of the large fires which had been alight since earlier in the season continued to burn within containment lines. Lightning over the ranges to the east of Melbourne on the last day of February and first day of March, and again on the 4th, sparked multiple new fires. There were around 30 fires were burning by 5 March.
Several fires became very large, including in Bunyip State Park southeast of Melbourne, at Yinnar South in South Gippsland, in Alpine National Park at Licola, northwest of Dargo, and near Omeo. Numerous other fires were also started by lightning early in the month, including at Rosedale, Timbarra, Walhalla, Aberfeldy, and Cambarville. For further details see the Significant Weather section of the March Monthly Weather Review.
Severe thunderstorms, associated with a coastal trough, produced giant hail, flash flooding, and heavy falls across Greater Sydney on the evening of 14 March. More than 620 calls were made to the SES, while Mona Vale Golf Club (in the Northern Beaches) recorded 120.8 mm in two hours.
On the evening of 22 March, a thunderstorm associated with a low pressure trough delivered heavy rain and hail to eastern parts of Greater Melbourne. The SES received more than 70 calls, mostly for building damage, flash flooding, and downed trees.
A strong cold front crossed Victoria between the afternoon of 22nd and the evening of 24th, bringing an end to a week-long spell of warm and unusually humid weather. The front produced damaging winds, with many sites recording gusts in excess of 100 km/h. The SES responded to more than 140 calls for help, mostly for downed trees and building damage; around a third of the calls were from Melbourne.
Severe tropical cyclone Veronica was named in the early hours of 20 March while well offshore to the northwest of Western Australia. The system rapidly intensified and maintained category 4 strength between the 21st and 23rd as it moved southwest then south towards the Pilbara coast. Veronica moved very close to the coast, west of Port Hedland at category 3 strength on the 24th, and remained near-stationary for the next 24 hours before tracking westwards and weakening to below tropical cyclone strength by the 26th. Major flooding resulted along the Pilbara coast with both Port Hedland and Karratha cut off by flooding and multiple roads closed in the region, including the Great Northern Highway and North West Coastal Highway. More details can be found in the report on severe tropical cyclone Veronica.
Severe tropical cyclone Trevor was named off the east coast of Queensland's Cape York Peninsula early on 18 March, then intensified rapidly before making landfall just south of Lockhart River at category 3 strength on the 19th. Trevor moved across the Cape York Peninsula and re-intensified over the Gulf of Carpentaria before making a second landfall east of Port McArthur in the Northern Territory as a category 4 system on the 23rd.
Trevor brought widespread heavy rainfall across Cape York Peninsula and Queensland's north tropical coast, as well as heavy rainfall about the southern coast of the Gulf. Some sites in Queensland had their highest March daily rainfall on record. Around 2500 people from remote communities along the Northern Territory's western Gulf coast were evacuated into temporary accommodation ahead of the cyclone's landfall. The remnants of the ex-tropical cyclone continued to produce rainfall over the east of the Northern Territory and western Queensland, and contributed to heavy rainfall over eastern Australia associated with the passage of a trough and cold front at the end of the month. In north Queensland, trees were defoliated and felled, buildings were damaged at Lockhart River, and roads were cut due to localised flooding. Some rain from this event made its way to Lake Eyre / Kati Thanda in South Australia, joining floodwaters from other events earlier in the year.
More details can be found in the report on severe tropical cyclone Trevor.
Major flooding across western Queensland which had started in February, and was extended by heavy rainfall associated with ex-tropical cyclone Trevor at the end of March, continued into April.
Major flood levels were recorded across the Channel Country catchments (Georgina/Eyre, Diamantina, and Thomson/Barcoo/Cooper). Significant flooding was also recorded in the Bulloo, Paroo, and Warrego catchments during early to mid-April but the most significant flooding was recorded further to the west.
Inflows into Lake Eyre / Kati Thanda from earlier in the year had left the Lake about half covered, with further inflows into Lake Eyre / Kati Thanda continuing throughout April, May, and June. In whole, the 2019 event was the most significant filling event for the Lake since 2010–11, with at least 65% of the Lake covered by water. The 1974 event resulted in the Lake being completely covered, while in 2011 it was at least 85% covered.
Windy conditions affected western and southern South Australia ahead of a strong front on 5 April. Strong to gale force and gusty north to northwesterly winds developed from mid-morning over the Eyre Peninsula and central districts, with the strongest winds over the south of the peninsula during the early afternoon. The SES responded to 74 requests for assistance, most related to downed trees and other wind related damage.
Unusually warm and dry weather during April, combined with windy conditions, led to elevated fire danger and significant areas of raised dust across southern South Australia, including across the Adelaide area. Low visibility from the thick dust created hazardous road conditions and South Australian Police closed the Augusta Highway near Port Wakefield for a period. The dust contributed to ambulance staff attending to a higher than usual number of patients with breathing difficulties.
A dust storm moved through Mildura on 7 May, fuelled by gust front with wind gusts over 80 km/h, reducing visibility to a few hundred metres. Dust storms are most often seen in summer, however northwest Victoria had been very dry for a number of months.
A cold front and a low pressure system that crossed Victoria on 9 and 10 May brought heavy rainfall and flash flooding to Ballarat and Geelong, as well as snowfalls in the Victorian Alps. A slow-moving thunderstorm cell developed over Cape Paterson on 10 May, resulting in large accumulation of small hail in the area.
Several cold fronts brought significant rainfall and strong wind gusts to the South West Land Division (SWLD) between 6 and 11 June. Ahead of the passage of cold fronts, gusty northerly winds combined with very low dewpoints produced severe fire danger situations across inland parts of the SWLD, and several fires were burning out of control on the 6th, including at Jarrahwood. A tornado was reported at Lake Nowergup around midday on the 10th. About 40 trees were damaged. Gabbadah, north of the Perth area, reported a roof torn off by a possible tornado. The SES received 183 calls for roof and structural damage, water ingress, and downed trees.
Tides were very high along the west coast and many places experienced beach erosion and inundation. Large pools of water inundated paddocks around Tooradin, with some linked to channels; beaches were eroded at Fremantle, Geraldton, and Lancelin, and Busselton jetty was almost completely submerged.
During the afternoon and early evening on 10 July cold fronts brought strong to gale force northwesterly winds to southern South Australia ahead of the front, followed by squally winds, heavy showers and thunderstorms with the passage of the front itself. Emergency services responded to about 180 requests for assistance, mostly in the Mount Lofty Ranges and the South East. A tornado cut a narrow path of damage through eucalyptus trees on a farming property at Avenue Range, near Lucindale.
Strong to gale force northwest winds ahead of a front and low affected most parts of the Mount Lofty Ranges from the Barossa to Victor Harbor during the afternoon on the 23rd. Emergency services responded to about 60 requests for assistance, including eight from Southend where the pattern of damage was consistent with a short-lived tornado.
A strong cold front produced a cold outbreak in southeast Australia from 7 August, bringing damaging winds, squally showers, and storms.
In South Australia storms on the 8th brought strong and damaging winds and localised flooding to the Adelaide Hills, with power blackouts affecting thousands of properties across the State. During the 9th, there were sustained strong winds over parts of West and South Gippsland and coastal southwest Victoria.
The Victorian SES received more than 500 calls, mostly due to fallen trees and some building damage, while the New South Wales SES received close to 300 calls, mostly from the Illawarra and South Coast.
The cold outbreak brought widespread heavy snow to many elevated areas in New South Wales and Victoria. Moderate falls were reported in the highlands of New South Wales with many locations above about 600 m receiving settling snow on 10 and 11 August, including Orange, Guyra, Lithgow, higher parts of Canberra, the Barrington Tops, and the Blue Mountains, and widespread snow falling to lower levels in Victoria, including Mt Macedon and the Dandenong Ranges. In Victoria this was the most widespread low level snowfall since 2008. Over a metre of snow fell at Spencers Creek during the month, mostly between the 6th and the 13th.
Extremely dry conditions and very much above average temperatures led to increased fire risk across New South Wales and Queensland during spring.
In Queensland, more than 50 fires were burning by 7 September, rising to 70 on the morning of the 11th and totalling more than 33 000 hectares statewide. By the 11th, QFES had confirmed properties had been lost at Binna Burra, Applethorpe and Stanthorpe, Sarabah, Peregian Beach, and near Mareeba in the Atherton Tablelands. Evacuations were ordered for parts of Beechmont and Binna Burra in the Gold Coast Hinterland, and Stanthorpe and Applethorpe in the Granite Belt.
In New South Wales, more than 50 fires were active by 9 September, with five fires were burning out of control and three watch and act alerts in place: for the Long Gully Road fire at Drake near Tenterfield, the Bees Nest fire near Armidale, and the Shark Creek fire in the Clarence Valley. By the 12th, the Bees Nest fire had reached 78 600 hectares. The fire at Shark Creek still burnt in bushland in the Yuraygir National Park and Shark Creek area, south of Yamba, having reached 10 100 hectares. The fire at Long Gully Road continued to burn in bushland south of Drake, Tabulam, and the Bruxner Highway, having reached 47 500 hectares.
More details on the fires and associated weather conditions can be found in Special Climate Statement Severe fire weather conditions in southeast Queensland and northeast New South Wales in September 2019.
Cold nights during the first half of September led to severe frost damage to crops in southwest Western Australia, with greatest losses in the region around Esperance. Low minimum temperature records for September were set at some sites, including −5.5 °C at both Eyre and Salmon Gums Research Station.
The effect of the frost was compounded by antecedent low rainfall, and high temperatures following frost early in the month, as well as crops being at a vulnerable stage of development. Reports indicated crop damage from the frost events may be the worst for a decade or more.
A cold spell mid-month also saw frost cause crop damage across southeastern South Australia and parts of western Victoria on the 17th and 18th. Snow fell overnight in most parts of Canberra overnight of the 16th but had mostly melted by morning due to rain followed by warmer temperatures. Some areas had settled snow, with 5 cm to 8 cm at Goulburn.
A number of the large fires which had started in September in New South Wales and eastern Queensland continued to burn throughout October.
In the region near Tenterfield, on 9 October the Long Gully Road fire near Drake joined with the western edge of the Busbys Flat fire near Rappville. The Busbys Flat fire had started during 4 October, and by the 9th the combined area burnt by both fires was more than 78 000 hectares.
Hot, dry and windy conditions ahead of a cold front passing through southeastern Australia on the 25th led to elevated fire dangers across parts of eastern Australia, with renewed fire activity in northeastern New South Wales and southeastern Queensland.
Further property losses occurred during the month in both New South Wales and Queensland, and several lives were lost in New South Wales.
Details on some of these fires, and the antecedent conditions, can be found in Special Climate Statement Dangerous bushfire weather and heat in spring 2019.
A hail storm in the Riverland District of South Australia on the evening of 4 November caused crop damage along a narrow band between Murray Bridge and Renmark. Most of the affected properties were vineyards, but areas of stone fruit, nuts, citrus, and dryland cereal were also affected.
Westerly winds were more frequent and stronger than usual over southern Australia during November. Most automatic weather stations in the southeast of the country had their highest November mean wind speed on record (although in most cases this record only goes back 10 to 20 years), and several had their strongest November wind gust on record.
A fire at Port Lincoln, on South Australia's Eyre Peninsula, on the 12th burned about 5000 hectares and damaged at least 11 properties.
Between 18 and 21 November many high temperature records were set across southern Australia. A cool change with very dry air, and very strong and gusty winds led to a worsening of the fire situation with lightning leading to the ignition of many new fires on the 21st. The Victorian SES received more than 1000 requests for assistance, with widespread blackouts, and high winds leading to damage and transport disruptions in and around Melbourne.
In Victoria there were around 60 fires active on 21 November, including large fires in northern Victoria at Rochester near Shepparton, three large fires in East Gippsland near Bruthen, Gelantipy, and Ensay, and a fast-moving grass fire at Mount Glasgow, north of Ballarat.
By the 25th the Bruthen fire was 850 hectares and the Gelantipy fire 600 hectares, while in the northeast of the State, a 300 hectare fire was burning in the Mount Bogong area.
More details on dangerous bushfire weather and heat in spring 2019 can be found in the related Special Climate Statement.
On 17 November, severe thunderstorms developed over southeast Queensland. Large hail around 4 cm to 6 cm in diameter was reported around Caloundra, the Glass House Mountains, Mooloolaba, and Buderim. On the Gold Coast hail more than 4 cm in diameter was reported around Southport, Pacific Pines, and near Beenleigh, while hail of 2 cm to 4 cm in diameter was reported in suburbs to the east and north of Brisbane. Early reports estimated the damage bill as in excess of one hundred and twenty million dollars.
Widespread thunderstorm activity was observed across New South Wales associated with the passage of a strong cold front on 26 November. The storms were brief, but some were severe, with a large number of damaging wind gusts observed as a distinct line of thunderstorms moved across the east, sweeping through Sydney just after 1 pm.
Trees were felled, raised dust reduced visibility, and power was lost to 76 000 premises. The SES responded to 1279 requests for assistance across Sydney and the Blue Mountains.
Gusty westerly winds were stronger and more prevalent than usual through November and December in Tasmania. A large fire started west of Swansea on the East Coast, following lightning strikes in early December. Fanned by westerly winds on several occasions, the fire had burnt more than 4370 hectares by mid-December. Back burning to contain the fire brought smoke to East Coast communities on several days.
Several fires had also started in October and November, particularly in the northeast quarter of the State, and some continued to burn for several weeks. Details on some of these fires, and the antecedent conditions, can be found in Special Climate Statement Dangerous bushfire weather and heat in spring 2019.
Severe storms formed near the New South Wales border on the evening of 11 December, tracking near Applethorpe then over Brisbane. Very heavy rainfall led to flash flooding in the metropolitan region, with the Brisbane city gauge reporting 103 mm in one hour, delivering December's average rainfall total in one night. Emergency services received 125 calls for assistance.
Severe storms also formed on the 13th over southeast Queensland and the Wide Bay region. Very heavy rainfall affected the Gold Coast, while Brisbane experienced high winds, and a storm cell produced giant hail 8 cm to 10 cm in diameter at Wolvi and Wilsons Pocket (east-northeast of Gympie), and hail up to 11.5 cm in diameter at Goomboorian. There were unconfirmed reports of hail up to 13 cm in diameter at near Gympie. Hail of such large sizes is very rare in Australia.
Significant heat affected large parts of central and southern Australia from 12 December as a slow-moving high over the Great Australian Bight allowed heat to build over the continent. Temperatures in the mid to high 40s were observed across large areas, in cases for several consecutive days, including at Perth where temperatures reached 40 to 41 degrees each day from the 13th to 15th. As the extremely hot air mass moved eastward, large areas approached or exceeded December daily maximum temperature records across inland and southeastern South Australia, Victoria and New South Wales, southeast Queensland, Central Australia, and much of Tasmania. For a number of locations records were set for the warmest day for any time of the year. While fewer records were set in inland Queensland, areas of the south and west experienced temperatures exceeding 45 °C on multiple days.
On two consecutive days, the 17th and 18th, records were set for Australia's hottest day on record. The national area-averaged maximum temperature on the 18th was 41.9 °C, a whole degree above the value for the 17th (40.9 °C). Both of these values exceed the previous record of 40.30 °C set on 7 January 2013. The extreme heat during December also led to Australia's warmest week (week ending 24 December) and warmest month on record in terms of national area-averaged maximum temperature.
It is expected that a Special Climate Statement will be released covering this extreme heat event.
Dangerous fire weather conditions in early November had led to renewed fire activity in New South Wales and eastern Queensland, with the fires continuing to burn throughout December. Fire weather was particularly severe in spring over the eastern half of Australia, and over most of the country in December, where the monthly (accumulated) Forest Fire Danger Index (FFDI) was the highest on record for any month. Further significant fires also broke out during the month in South Australia, Gippsland and northeastern Victoria, across the Alpine region, southeastern New South Wales, and Tasmania. The end of year period brought particularly challenging weather, with the FFDI for individual days the highest on record for December, and in some cases for any month, on 30 and 31 December over areas of southeastern Australia and Tasmania. Thousands of people in eastern Victoria and southeastern New South Wales were affected by evacuation orders as the fires flared in these very dangerous conditions.
Widespread areas of heavy smoke created hazardous air quality across broad areas of eastern Australia at times during spring through December, in some locations lasting for weeks at a time with little respite.
By the end of December, more than 5 million hectares had been burnt across Australia since the start of July, including 3.6 million in New South Wales, half a million in Victoria, 250 000 hectares in Queensland, and more than 60 000 hectares in South Australia. At least 18 lives had been lost, while a number of people remained unaccounted for, and more than 1600 homes had been destroyed, the bulk of which were in New South Wales. The extensive and long-lived fires appear to be the largest in scale in the modern record in New South Wales, while the total area burnt appears to be the largest in a single recorded fire season for eastern Australia.
2019 monthly and annual rainfall, temperature and sea surface temperature deciles maps
All values in this statement were compiled from data available on the issue date. Subsequent quality control and the availability of additional data may later result in minor changes to values published elsewhere in the underlying datasets as compared to the values published in this statement.
The Bureau collects, manages and safeguards Australia's climate data archive. Several datasets have been developed from this archive to identify, monitor, and attribute changes in the Australian climate. You can access these datasets on our website. The datasets used in the preparation of this statement are outlined below.
Area-averaged temperature values are from the homogenised Australian temperature dataset (ACORN-SAT)
Mapped temperature analyses use AWAP temperature data.
Area-averaged rainfall values and mapped monthly analyses use the AGCD dataset (replacing the AWAP dataset used in Annual Climate Statements for 2019 and earlier years).
Sea surface temperature data are from the NOAA Extended Reconstructed Sea Surface Temperature dataset, ERSST
Soil moisture analysis uses Australian Water Resources Assessment Landscape model (AWRA-L) data
Atmospheric gas charts use data from CSIRO Kennaook / Cape Grim Baseline Air Pollution Station (KCG BAPS)
Sea-ice extent values use data from the National Snow and Ice Data Center, University of Colorado, Boulder – Nimbus-7 SMMR and DMSP SSM/I-SSMIS Passive Microwave Data for 1979 to the year before last, and Near-Real-Time DMSP SSM/I-SSMIS Daily Polar Gridded Sea Ice Concentrations for observations during the most recent year
A note on base periods
In climatology a baseline, or long-term average, is required against which to compare changes in climate over time. The Bureau uses the 1961–1990 period as the climate reference period for the Annual Climate Statement and other climate monitoring products.
A minimum 30 years of data is required to form a robust climatological average, accounting for decadal variability. In general, baseline climatological periods try to make use of the period with the best data coverage. The 1961–1990 period is comparable to the first 30-year period where there is good global coverage of climate data, and is thus used as a benchmark for reporting climate change allowing consistent comparison of national temperature observations across countries. However alternate averaging periods are also used for other purposes, such as facilitating comparison to a more recent period for climate outlooks, or to the pre-industrial period for long-term climate change.
The choice of base period is a convention. It has no bearing on the calculation of trends over time, or the ranking of one year compared to all other years in a dataset.
Unless otherwise noted, all maps, graphs and diagrams in this page are licensed under the Creative Commons Attribution 4.0 International Licence
Product code: IDCKGC5AR0