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.
Rainfall deficiencies re-emerge in southeast Queensland
February rainfall was below average across much of Queensland (particularly south of a line between Boulia and Townsville), most of New South Wales (except the southeast), northeastern South Australia, and also across much of Tasmania away from the west. Rainfall for the month was above average for most of Western Australia, the Top End of the Northern Territory and the southern Gulf coast in Queensland, and also for areas along a line extending from the west coast of South Australia, through the eastern Eyre Peninsula, across the Murraylands and Adelaide region, and into northwest Victoria.
Rainfall has often been below average in areas along and east of the Great Dividing Range in the months since October 2016. The summer months have also been particularly warm for much of New South Wales and southern Queensland. A persistent upper-level pressure ridge remained over the continent for several weeks, positioned further south than is typical for the season and extending as far east as Lord Howe Island, which has also received below average rainfall. This ridge brought large-scale subsidence (sinking air) and reduced cloudiness during January and February, while a series of slow-moving high pressure systems over the Tasman Sea further contributed to conditions conducive to hot, dry weather in eastern Australia.
The latest Climate Outlook suggests that a drier than average autumn is likely for southern and central Australia.
4-month rainfall deficiencies
Areas of serious to severe rainfall deficiencies are present at the four-month timescale across greater southeastern Queensland (roughly southeast of a line between Rockhampton and Cunnamulla, with the area affected closer to the southern border becoming focused on the Darling Downs), while scattered localities around central eastern Queensland are also experiencing deficiencies.
Serious deficiencies extend into parts northern New South Wales in the Northwest Slopes and Plains district, and in a coastal pocket around Kempsey. A small area of deficiencies also exists in Gippsland in eastern Victoria, and adjacent far southeastern New South Wales.
Surrounding the regions experiencing serious rainfall deficiencies are large areas which are in decile 2 for November to February, meaning they have received rainfall in the lowest 20% of historical observations (serious rainfall deficiencies are analysed for areas with rainfall in decile 1, the lowest 10% of historical observations). Localities in decile 2 across central to eastern Queensland, northern New South Wales, and eastern Victoria to southeastern New South Wales will continue to be closely monitored for further developments.
Soil moisture in the lower layer (from 10 cm to 100 cm deep) decreased across much of the eastern mainland States from January into February. Soil moisture for February was below average for the eastern half of Queensland south of the Cape York Peninsula, the eastern half of New South Wales and the Riverina district, and parts of Gippsland in eastern Victoria.
Soil moisture increased across southwest Western Australia following very much above average rainfall during February. Soil moisture for the month was above average for Western Australia, the Northern Territory and South Australia; parts of Victoria in the northwest, southwest and central southern coast and in pockets of the northeast and central north; parts of the Gulf Country and around Birdsville in Queensland; and across most of Tasmania.
- February rainfall below average for much of Queensland, New South Wales, northeastern South Australia, and Tasmania
- Serious to severe rainfall deficiencies are present at the 4-month timescale in greater southeastern Queensland and northern New South Wales
- Soil moisture below average across much of the east of the eastern mainland States
Product code: IDCKGD0AR0