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.

Map of 3-month rainfall deficiencies for Australia for January to March 2019

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


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.

This section displays rainfall maps. Current drought status is described in the previous section. For historical drought status statements, go to archive of drought statements

Also available at Maps – recent conditions

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

Median rainfall map, links to climate average maps An area experiences a rainfall deficit when the total rain received is less than the average rainfall for that period.

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: