Rainfall deficiencies persist; increase in parts of the east and north
January rainfall was below or very much below average across the southeastern quarter of Queensland, northeastern New South Wales, Victoria and adjacent southern New South Wales, southern South Australia, Tasmania, most of the southern half of Western Australia, most of the Northern Territory (except the Top End) and adjacent western Queensland. A large number of stations in the southeastern quarter of Queensland received record-low rainfall for January.
Rainfall was very much below average for southern Victoria and much of southern South Australia, while for Tasmania as a whole it was the driest January on record.
Tropical systems contributed to above average rainfall along the coast of central and northern Queensland, and small in central northern Queensland and the Top End, and central eastern New South Wales.
The delayed onset of the Australian monsoon during the summer of 2018–19 has seen below average rainfall for the northern wet season to date over most of northern Australia, excluding Queensland's tropical and central coast, and the northeastern Top End. This has led to the emergence of serious or severe rainfall deficiencies over parts of northern Australia at the 4-month timescale.
A slow-moving monsoon trough has produced, and will continue to produce, heavy rain across northern Queensland during late January to early February. Multi-day totals for the first 5 days of February exceeded 400 mm across a broad area, and while the heaviest rain has so far been on the coast in the region surrounding Townsville, there have been locally very high (but patchy) falls in inland northern Queensland, including an area north of Mount Isa. It is likely that a Special Climate Statement will be released for this event.
Rainfall has been below average over the region for a number of months (periods beginning April 2018) and the deficits in place are quite large. While this current event will go far towards relieving rainfall deficiencies, and may remove short-term deficiencies (particularly immediately north of Mt Isa), is unlikely to clear long-term deficits completely, and some areas will miss out.
The lack of rainfall over northern Australia during summer has also been a primary influence on the prolonged heat events which have affected Australia since early December 2018. Both the scale and longevity of this persistent heat is unprecedented and January was the warmest on record for Australia; further information can be found in the Special Climate Statement Widespread heatwaves during December 2018 and January 2019.
Rainfall deficiencies for the longer 10-month period have also increased across northern Australia, and have generally increased slightly across eastern South Australia and the eastern mainland at both the 10- and 22-month timescales.
4-month rainfall deficiencies
Northern Australia receives the bulk of its rainfall between October and April (the northern wet season), so rainfall deficiencies during this period are particularly significant, and will not usually be removed before the following wet season.
For the 2018–19 northern wet season so far, rainfall has been below average over most of northern Australia, excluding Queensland's tropical and central coast, and the northeastern Top End. Serious or severe rainfall deficiencies for the period starting October 2018 affect scattered pockets of the north of Western Australia, a large area in the central Northern Territory and smaller areas spanning the border and adjacent parts of western Queensland, and an area inland of the ranges in the southeastern quarter of Queensland.
Rainfall during this period has also been particularly low over Tasmania, with severe deficiencies across the west of the State.
10-month rainfall deficiencies
Southern Australia receives the bulk of its rainfall between April and November (the southern wet season), so rainfall deficiencies during this period are particularly significant.
While December brought above average rain for parts of the mainland southeast, high rainfall after the end of the main agricultural and runoff season has the effect of reducing rainfall deficiencies, but does not fully ameliorate the impact of earlier dry conditions.
January was very dry across large areas, and has seen deficiencies increase across much of eastern Australia and increase greatly across northern Australia.
Serious or severe rainfall deficiencies are in place across eastern South Australia (except the extreme southeastern tip) and adjacent parts of western New South Wales; across northern New South Wales away from the coast, and an area in the South West Slopes and Riverina districts; across Gippsland in Victoria; much of Queensland except the far southwest, Cape York Peninsula, and much of the central coast; a large part of the Northern Territory between the eastern border and central regions; an area of Western Australia in the southern Kimberley and northern Interior, and smaller areas in the northern Kimberley and in the Southeast Coastal District.
22-month rainfall deficiencies
As for the other periods, low January rainfall has generally seen rainfall deficiencies increase slightly, and emerge across parts of the Northern Territory.
Serious or severe rainfall deficiencies continue across most of New South Wales excluding the northeast coast and most southern regions away from the far southwest and inland of the coastal ranges; across much of eastern Victoria; areas of coastal eastern and northern Tasmania; much of the eastern half of South Australia away from the far southeast and far northeast; much of the southern and central Queensland away from the coastal ranges, and areas of western Queensland extending into parts of the Alice Springs and Barkly districts in the Northern Territory.
In Western Australia deficiencies persist along the coast between the Pilbara and the South Coastal District.
Compared to December, relative lower-layer soil moisture (from 10 cm to 100 cm deep) has decreased across nearly all of Australia.
Soil moisture for January was below average for the western half of Western Australia, across the Nullarbor and in pockets of the Kimberley; across most of the remainder of the mainland except for some areas in the west of the Northern Territory and central to eastern Top End, the northwest of South Australia, across the north and east of Cape York Peninsula and central coast Queensland, pockets of central eastern to southeastern New South Wales, northwestern Victoria, and northeastern Tasmania.
Soil moisture was above average for the north and east of Cape York Peninsula and pockets of Queensland's central coast, and also for pockets of the north east of the Top End, in the east of Western Australia in the north and south of the Interior District, and on the west coast near Geraldton.
- January rainfall very much below average for southeastern Queensland and much of southeastern Australia; driest January on record for Tasmania
- Rainfall above average for parts of northern coastal Queensland
- Short-term deficiencies have increased and are evident in western Tasmania and scattered areas of northern Australia at the 4-month timescale
- Deficiencies have increased at the 10-month timescale in much of eastern South Australia, the eastern mainland, and northern Australia
- Longer-term deficiencies continue with generally slight increases in most areas
- Lower-level soil moisture below average for January across most of Australia, except central west of Western Australia, parts of the Top End, and the northern and central Queensland coast
- Record-high temperatures added to moisture stress during January, following a record-warm December
Product code: IDCKGD0AR0
Soil moisture details are reported when there are periods of significant rainfall deficits.
Soil moisture data is from the Bureau's Australian Water Resources Assessment Landscape (AWRA-L) model, developed through the Water Information Research and Development Alliance between the Bureau and CSIRO.
See: Australian Landscape Water Balance.
What is drought?
Drought is a prolonged, abnormally dry period when the amount of available water is insufficient to meet our normal use. Drought is not simply low rainfall; if it was, much of inland Australia would be in almost perpetual drought. Because people use water in so many different ways, there is no universal definition of drought. Meteorologists monitor the extent and severity of drought in terms of rainfall deficiencies. Agriculturalists rate the impact on primary industries, hydrologists compare ground water levels, and sociologists define it by social expectations and perceptions.
It is generally difficult to compare one drought to another, since each drought differs in the seasonality, location, spatial extent and duration of the associated rainfall deficiencies. Additionally, each drought is accompanied by varying temperatures and soil moisture deficits.
Rainfall averages, variability and trends
- Average rainfall: How much rain do you expect?
- Rainfall variability: How consistent is rainfall in your area?
- Rainfall history: Check tables, graphs and data from your local weather station.
- Rainfall trends: Has your rainfall changed?
Lowest on record - lowest since at least 1900 when the data analysed begin.
Severe deficiency - rainfalls in the lowest 5% of historical totals.
Serious deficiency - rainfalls in the lowest 10% of historical totals, but not in the lowest 5%.
Very much below average - rainfalls in the lowest 10% of historical totals.
Below average - rainfalls in the lowest 30% of historical totals, but not in the lowest 10%.
Average - rainfalls in the middle 40% of historical totals.
Above average - rainfalls in the highest 30% of historical totals, but not in the highest 10%.
Very much above average - rainfalls in the highest 10% of historical totals.
For the week to 19 February 2019, rainfall was recorded across northern Australia, parts of the Pilbara in Western Australia, central and southeastern Queensland, southern Victoria and western Tasmania. Light falls were recorded in parts of southern Western Australia, southeastern South Australia, most of Victoria except the northwest, southeastern New South Wales, and eastern Tasmania.
At the start of the week, a cold front and pre-frontal trough tracked across southeast Australia and brought light to moderate falls to southern parts of Victoria, and western Tasmania. Light falls continued in western Tasmania into the middle of the week, associated with westerly flow.
Showers and isolated thunderstorms developed over the northeast of the Northern Territory and the Kimberley in Western Australia, while a surface trough along the east coast of Queensland triggered showers and thunderstorms, with moderate falls in southeast Queensland. As the week progressed, surface troughs extended along the west coast of Western Australia and across northern Australia, with another trough located through inland Queensland and New South Wales. These areas of low pressure generated isolated thunderstorms in parts of northern Western Australia, the north of the Northern Territory, and northern and eastern Queensland.
From the middle of the week, showers and thunderstorms developed across much of northern Australia, and along a surface trough that extended through central Queensland. The surface trough across northern Australia persisted until the end of the week, and brought moderate falls to the Kimberly in Western Australia, much of the north of the Northern Territory, and northern Queensland.
Rainfall totals exceeding 50 mm were recorded in northern parts of Cape York Peninsula in Queensland, isolated locations in the Top End in the Northern Territory, and isolated locations in the Kimberley in Western Australia. Totals in excess of 100 mm were recorded in the far north of Cape York Peninsula, including the highest weekly total of 158 mm at Merluna.
Rainfall totals between 10 mm and 50 mm were parts of the Kimberley and Pilbara in Western Australia; the northern third of the Northern Territory; parts of northern, central and southeastern Queensland; southern Victoria; and western Tasmania.
Little of no rainfall was recorded in remaining parts of Western Australia; the southern two thirds of the Northern Territory; western and southern Queensland; most of New South Wales; northwestern Victoria; and most of South Australia except in the State's southeast.
Impact of recent rainfall on deficits
The Drought Statement, issued on 6 February 2019, discusses rainfall deficits over Australia for the 4-month (October 2018–January 2019), 10-month (April 2018–January 2019) and 22-month (April 2017–January 2019) periods. Rainfall deficit maps are available for these periods as well as for standard periods.
The maps below show the percentage of mean rainfall that has been received for the rainfall deficit period for the 4-month, 11-month and 22-month periods ending 19 February 2019.
Rainfall for the period 1 October 2018 to 19 February 2019
For the 4-month time period, serious or severe rainfall deficiencies affect scattered pockets of the north of Western Australia, a large area in the central Northern Territory and smaller areas spanning the border and adjacent parts of western Queensland, and an area inland of the ranges in the southeastern quarter of Queensland. Rainfall deficiencies are also in place across the west of Tasmania.
There was very little change in rainfall deficiencies in affected areas in the past week. Affected areas of western Tasmania have generally received less than 80% of average rainfall. Affected areas of northern Australia have generally received less than 60% of average rainfall for the period, and less than 30% over parts of the central Northern Territory and Pilbara. Areas in Queensland's southern interior have received less than 50%, while areas in northwest Queensland have now received more than 100% of average.
Rainfall for the period 1 April 2018 to 19 February 2019
Serious or severe rainfall deficiencies for the 10-month period persist in the eastern half of South Australia except the far southeast and far northeast; adjacent parts of western New South Wales; across northern New South Wales away from the coast, and an area in the South West Slopes and Riverina districts; across Gippsland in Victoria; much of Queensland except the far southwest, Cape York Peninsula, and much of the central coast; a large part of the central Northern Territory; an area of inland northern Western Australia and smaller areas in the northern Kimberley and in the Southeast Coastal District.
The rain that fell over the past week had little impact on deficiencies. Affected areas of southern coastal Western Australia, southeastern South Australia, eastern Victoria, central to eastern parts of New South Wales and east coast Queensland have generally received between 50% and 70% of average rainfall for the period. Percentages of average totals are lower for the more arid regions experiencing deficiencies. Affected areas in northwestern New South Wales, northeastern South Australia, the central Northern Territory, and southwestern Queensland have generally received between 40% and 20% of average rainfall for the period.
Rainfall for the period 1 April 2017 to 19 February 2019
Serious or severe rainfall deficiencies persist at the 22-month time period continue across most of New South Wales excluding the northeast coast and most southern regions; across much of eastern Victoria; areas of coastal eastern and northern Tasmania; much of the eastern half of South Australia away from the far southeast and far northeast; much of the southern and central Queensland away from the coastal ranges, and areas of western Queensland extending into parts of the Alice Springs and Barkly districts in the Northern Territory.
The rain that fell in the past week had little impact on rainfall deficiencies in affected areas. Rainfall in affected areas of the southwest of Western Australia, southern South Australia, eastern Victoria, southern New South Wales and southeastern Queensland has generally been between 80% and 60% of average for the period. Inland Queensland, northwestern New South Wales, northeastern South Australia, and parts of coastal northwestern Western Australia have generally received between 50% and 30% of average rainfall for the period.
Product code: IDCKGRWAR0