Drought
Tropical cyclones bring limited relief in the north; deficiencies develop along the mainland south coast
Meteorological drought thresholds are being reached on different timescales in different areas, for example western Victoria is strongly affected for periods shorter than six months, while New South Wales is most affected for periods of one year or longer.
In addition to areas experiencing serious or severe deficiencies (rainfall for the period in decile 1, the lowest 10% of historical observations), rainfall has been below average (in decile 3 or below, the lowest 30% of historical observations) across very large areas for periods of 12 months to 24 months in length. While falling outside the threshold for meteorological drought, those areas will also be feeling the effects of below average rainfall over a prolonged period. The length and severity of this ongoing drought is unusual and significant; a Special Climate Statement providing further detail on the rainfall situation will be released in the coming days.
Two severe tropical cyclones contributed to above to very much above average March rainfall in far northern Queensland, the southern Gulf of Carpentaria coast, western to central Queensland and parts of the south and southeast of that State, the east of the Northern Territory, northeast South Australia, and part of the Pilbara coast. Rainfall was also above average for the month in much of eastern New South Wales and far eastern Victoria.
Following this rainfall, deficiencies have eased at timescales out to 24 months in parts of central to western Queensland, the southeast of the Northern Territory, and in the Pilbara.
March rainfall was below average to very much below average in a wide band from the Kimberley and Top End down to the top of the Great Australian Bight, across southern South Australia and Victoria, in northern and eastern Tasmania, and pockets along the west coast of Western Australia. Consequently, deficiencies have intensified in parts of the west and north of Western Australia, and the northwest to central Northern Territory. Deficiencies have also increased slightly across some areas of the southeastern mainland and South Australia.
The first three months of 2019 have been particularly dry for areas of the southern coast of the mainland, the west coast of Western Australia, northeastern New South Wales and the greater southeast of Queensland, as well as through the arid interior of Australia and the northern central Northern Territory. Serious or severe rainfall deficiencies for the three months January to March 2019 are shown in the map below.
Dry and unusually warm conditions, both for March individually and for January–March collectively, have reduced soil moisture and dried the landscape. Many farmers in southern Australia look to the autumn break—sometimes defined as the first significant rain event (25 mm or more) after summer—as the marker starting the crop and pasture growing season. In much of southern Australia that rain event has not yet come.
The southern wet season spans from April to November, and the Climate Outlook for April and May indicates an average to slightly lower than average chance of exceeding median rainfall across southern Australia for those months, which does not suggest these rainfall deficits are likely to be removed quickly.
6-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. With only one month to go, rainfall for the 2018–19 northern wet season has been below average over most of the Northern Territory, the northern half of Western Australia, and most of the southern half of Queensland.
Heavy rainfall during March has decreased or removed deficiencies in the inland southeast of Queensland, the Pilbara in Western Australia, and in parts of central southern Northern Territory.
Conversely, deficiencies have increased between the northwest and the centre of the Northern Territory, and in the Kimberley and along the west coast of Western Australia. Deficiencies have also increased in parts of eastern South Australia, northern New South Wales and border regions of southern Queensland, southern Victoria, and northwestern Tasmania.
Serious or severe rainfall deficiencies for the six-month period starting October 2018 are apparent in the northern Kimberley, areas of the southeastern Kimberley and northeastern Pilbara, and along large areas of the west coast of Western Australia between the western Pilbara and Perth; a very large area in the central Northern Territory and pockets of the western Top End coast; along the border of New South Wales and Queensland, and in an area around the Maranoa and southern Central Highlands in Queensland; in the west and south of Tasmania; and scattered pockets between northwestern New South Wales and Gulf St Vincent in South Australia, and in southern Victoria.
12-month rainfall deficiencies
Rainfall during March has reduced deficiencies in central to southwestern Queensland and parts of the southeast of that State, and reduced or removed deficiencies in far northeastern South Australia, the southeast of the Northern Territory, and the Pilbara and western Kimberley in Western Australia. Deficiencies have also decreased compared to last month at the southern edge of the area affected in northeastern New South Wales.
Compared to last month, deficiencies have increased across much of the Northern Territory away from the east, and in adjacent parts of Western Australia's Interior District and the northern Kimberley. Deficiencies have also increased somewhat in central and southern South Australia, and about the Riverina in New South Wales and northern Victoria.
Serious or severe rainfall deficiencies are in place across central to eastern South Australia away from the far northeast and far southeast; across much of central southern and eastern Victoria, and along the border in the central north and northwest of that State; across much of the Riverina in New South Wales as well as much of the west and north of that State; most of southern Queensland, extending north to around Taroom and Rockhampton; much of the Northern Territory except parts of the southwest, east, and Top End; and across much of the Kimberley, northern half of the Interior District, and adjacent eastern Pilbara in Western Australia, as well as areas in the Gascoyne, and much of the South Coast and Southeast Coastal districts.
24-month rainfall deficiencies
Rainfall during March has reduced deficiencies in northwestern Queensland and parts of the adjacent Alice Springs District in the Northern Territory, and at the northern edge of deficiencies affecting central and southern Queensland.
Elsewhere deficiencies have generally remained similar to those reported last month, although they have increased in the central Northern Territory and along the edge of existing deficiencies in west coast Western Australia, southern South Australia, and around the border between Victoria and New South Wales.
Serious or severe rainfall deficiencies persist across southern and central Queensland, except for the coastal southeast and most of the Wide Bay and Burnett District, and also for parts of the west of the State in the Channel Country; most of New South Wales, except the northeast coast, southeast, and Southwest Plains; across eastern Victoria and much of the Central District; along the coast of eastern and northern Tasmania; much of the eastern half of South Australia away from the far southeast and far northeast, and most of the Eyre Peninsula.
Deficiencies are also in place in a large area of the central Northern Territory, affecting the northern Alice Springs District, the Barkly District and the southeast of the Victoria River District.
In Western Australia deficiencies are in place along the coast from about Karratha in the Pilbara to east of Esperance, near the western edge of the Great Australian Bight.
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Soil moisture
Compared to February, there has been a decrease in relative lower-layer soil moisture (from 10 cm to 100 cm deep) across most of Australia, with the only increases in central northern to northwestern Queensland, and small pockets of the Pilbara and western Tasmania.
Soil moisture for March was below average for most of the southern half of Australia, extending into the Capricornia District of Queensland, the western Pilbara in Western Australia, and across much of the Northern Territory, Queensland's Gulf Country and Peninsula, and Western Australia's Kimberley.
Soil moisture in northern Australia would typically be at its wettest in February and March, with significant increases occurring from October to March. Much of the Northern Territory and northern Western Australia have not seen this increase, with soil moisture for March actually dropping below the levels seen in November over a large area north of Alice Springs.
Lower-layer soil moisture remains above average for an area of central to western Queensland, extending just into the Alice Springs District of the Northern Territory, and also smaller areas in the Pilbara and just north of Albany in southwest Western Australia.
- March rainfall mixed: above average for large parts of eastern Australia and the northern Pilbara, below average across much of northern, central, and southern Australia
- Rainfall have further reduced in central Queensland following heavy rain in northern parts of that State during February and March
- Deficiencies also eased in the southeastern Northern Territory and the Pilbara
- A dry start to the year in most other areas
- Lower-level soil moisture below average for March across most of Australia, above average for small areas in western Queensland and the Pilbara
- Warmest March on record for Australia continues a run of warm months, adding to moisture stress
Product code: IDCKGD0AR0
- See also:Links open in new window
- Water storages
- Groundwater
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.
Also available at Weekly Rainfall Updates
Also available at Maps – recent conditions
Rainfall and temperature outlooks
Rainfall and temperature outlooks outline likely conditions over three-month periods. Outlooks are available for single months, three months, and for any location in Australia. Formats include text summaries, maps, graphs and video.
Seasonal streamflow forecasts
Australian streamflows are among the most variable in the world. Seasonal streamflow forecasts extends water management decision making capability. Forecasts are issued monthly.
AWRA-L water balance maps
Australian Water Resources Assessment Landscape maps include maps of soil moisture and water fluxes contributing to changes in soil moisture (rainfall, transpiration, soil evaporation, surface runoff and deep drainage).
Climate statements archive
The archive includes previous monthly, seasonal and annual climate summaries for nation-wide, state/territory and capital city conditions.
- Water Information
Water resources assessments and forecasts - Water and the Land
Weather and climate for primary industries - Australian Bureau of Agricultural and Resource Economics and Sciences
(ABARES) is a research bureau within the Department of Agriculture, Fisheries and Forestry aimed at Australia's primary industries. - Climate Change in Australia
Bureau/CSIRO website, including rainfall and temperature projections and impacts for the coming decades. - CSIRO-BoM Drought-EC Report (July 2008)
An assessment of the impact of climate change on the nature and frequency of exceptional climatic events, and accompanying Supplementary Information.
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
An area experiences a rainfall deficit when the total rain received is less than the average rainfall for that period.
- 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?
Definitions
Definitions
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.
Australian Government drought assistance
Department of Agriculture and Water Resources information and contacts:
Archive
For the week to 23 April 2019, rainfall was recorded in the western Kimberley, parts of the central interior, southwest and south coast of Western Australia; areas of Arnhem Land in the Northern Territory; eastern, central and southwest Queensland; western, southern and northeastern New South Wales; central to northeastern Victoria; parts of southern South Australia, and Tasmania.
At the start of the week, onshore flow and surface troughs produced showers and light to moderate falls in Queensland's north tropical and southeast coasts, into northeastern New South Wales. A cold front tracked across southeast Australia, with embedded thunderstorms in a vigorous westerly flow producing moderate falls in western Tasmania. Another strong cold front crossed southwest Western Australia, bringing gusty winds and moderate falls to the southwest and parts of the southern coast of that State. A pre-frontal trough triggered isolated thunderstorms through parts of the Interior districts of Western Australia, while showers developed along a broad surface trough over the west Kimberley coast.
By the middle of the week, the second cold front tracked across southern parts of South Australia, with a pool of cold and unstable air with isolated thunderstorms behind the front generating moderate falls in the South West Coast and Eyre Peninsula districts. A high pressure ridge along the east coast of Australia produced onshore showers, generating moderate falls in Queensland's north tropical and southeast coasts, and northeastern New South Wales.
In the second half of the week, the cold front had tracked across southeastern Australia, with a surface trough stretching north through western Queensland. Light falls were reported in eastern South Australia, central to northeastern Victoria, and Tasmania. An upper level low and the associated trough through western Queensland generated a cloudband that extended through the eastern interior of Australia.
Embedded thunderstorms produced moderate falls in western to central New South Wales, and parts of southwest Queensland, extending into areas of central Queensland. Onshore winds continued to generate showers and moderate falls along the Queensland and New South Wales coasts to the end of the week.
Isolated thunderstorms and showers produced light to moderate falls across much of Arnhem Land in the Northern Territory throughout the week.
Rainfall totals in excess of 100 mm were recorded in the north tropical and southeast Queensland coasts, and northeastern New South Wales. The highest weekly total was 177 mm at Bingil Bay, located in the north tropical coast of Queensland.
Rainfall totals in excess of 50 mm were recorded in the far southwest of Western Australia; western Tasmania; in the northeast and northwest of New South Wales, and about the southwest interior, southeast, central, and north tropical coasts of Queensland.
Rainfall totals between 10 mm and 50 mm were recorded in the western Kimberley, southwest and parts of the southern coast of Western Australia; areas of Arnhem Land in the Northern Territory; the southwest coast of South Australia; most of Tasmania; northeastern Victoria and much of western and northeastern New South Wales.
Little or no rainfall was recorded in remaining parts of Western Australia, the Northern Territory and South Australia; the western half and parts of southeastern Victoria; the central interior to central coast of New South Wales; the southeastern interior, and much of central to western Queensland.
Impact of recent rainfall on deficits
The Drought Statement, issued on 3 April 2019, discusses rainfall deficits over Australia for the 6-month (October 2018–March 2019), 12-month (April 2018– March 2019) and 24-month (April 2017– March 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 6-month, 12-month and 24-month periods ending 23 April 2019.
Rainfall for the period 1 October 2018 to 23 April 2019
For the 6-month period, serious or severe rainfall deficiencies are evident in the northern Kimberley, areas of the southeastern Kimberley and northeastern Pilbara, and along large areas of the west coast of Western Australia between the western Pilbara and Perth; a very large area in the central Northern Territory and pockets of the western Top End coast; along the border of New South Wales and Queensland, and in an area around the Maranoa and southern Central Highlands in Queensland; in the west and south of Tasmania; and scattered pockets between northwestern New South Wales and Gulf St Vincent in South Australia, and in southern Victoria.
Rainfall over the last week has eased deficiencies in areas of the Maranoa and southern parts of the Central Highlands in Queensland, but had little impact on deficiencies elsewhere at this time scale.
Affected areas of western Tasmania, southern Victoria, and western Top End have generally received less than 80% of average rainfall for the period. Areas in southern Queensland, northern New South Wales, and the Kimberley in Western Australia have generally received between 30% and 60% of average. Areas in the northeast and west of the Pilbara and the central Northern Territory generally received less than 40% of average.
Rainfall for the period 1 April 2018 to 23 April 2019
Serious or severe rainfall deficiencies are in place at the 12-month period across central to eastern South Australia away from the far northeast and far southeastern; across much of central southern and eastern Victoria, and along the border in the central north and northwest of that State; across much of the Riverina in New South Wales as well as much of the west and north of that State; most of southern Queensland, extending north to around Taroom and Rockhampton; much of the Northern Territory except parts of the southwest, east, and Top End; and across much of the Kimberley, northern half of the Interior District, and adjacent eastern Pilbara in Western Australia, as well as areas in the Gascoyne, and much of the South Coast and Southeast Coastal districts.
The rain that fell over the last week has eased deficiencies slightly in parts of northwestern and northern New South Wales, and across the border in the southwest interior of Queensland.
Affected areas have generally received 20% to 70% of average for the period, with higher percentages towards the coast and lower percentages inland. Some areas in central parts of the Northern Territory, the eastern Pilbara in Western Australia, northeastern South Australia, northwestern New South Wales, and southwest Queensland have received less than 40% of average.
Rainfall for the period 1 April 2017 to 23 April 2019
Serious or severe rainfall deficiencies at the 24-month time scale are evident across southern and central Queensland, except for the coastal southeast and most of the Wide Bay and Burnett District, and also for some western areas of the State in the Channel Country; most of New South Wales, except the northeast coast, southeast, and Southwest Plains; across eastern Victoria and much of the Central District; along the coast of eastern and northern Tasmania; much of the eastern half of South Australia away from the far southeast and far northeast, and most of the Eyre Peninsula.
Deficiencies are also in place in a large area of the central Northern Territory, affecting the northern Alice Springs District, the Barkly District and the southeast of the Victoria River District. In Western Australia, deficiencies are in place along the coast from about Karratha in the Pilbara to just east of Esperance on the south coast.
Rainfall over the past week has eased deficiencies in an area of the southwestern interior of Queensland, and in the northwest of New South Wales, but had little impact on deficiencies elsewhere at the 24-month time scale.
Areas about the coastal western Pilbara, northeastern South Australia, northwest New South Wales and southwest Queensland received less than 40% of average for the period. Large areas of western and northern New South Wales, central and southern Queensland and the central Northern Territory, the coastal Gascoyne in Western Australia have generally received less than 60% of average rainfall for the period. For affected areas in southwest and south coast Western Australia, southern South Australia, Victoria, and Tasmania rainfall for the period has generally been between 60% and 80% of average.
Product code: IDCKGRWAR0
