A very dry month for the southeastern mainland increases rainfall deficiencies
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?
Go to Bureau Blog: 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.
Australian Government drought assistance
Department of Agriculture and Water Resources information and contacts:
- Know your weather
Know your weather. Know your risk.
- 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.
Rainfall deficiencies increase in Western Australia, South Australia, Tasmania; and emerge in West Gippsland in Victoria
June rainfall was below average for most of Australia, and lowest on record for much of inland northern and northeastern Victoria, adjacent inland southern New South Wales, southwest and western Western Australia, and eastern Tasmania. Rainfall was also below average for seasonally dry areas of northern Western Australia, the Northern Territory, and Queensland, and also below average for some areas of east coast Queensland which typically do receive rainfall during June.
Nationally, the area-averaged June rainfall was 62% below the long-term mean, coming in as the second-driest June on record. Across the country over 100 stations with more than 50 years of observations have reported their lowest June rainfall total on record. This very dry June was largely due to very much higher than average mean sea level pressure (MSLP) across southern Australia, associated with a positive phase of the Southern Annular Mode (SAM).
As a consequence of June’s exceptional dryness, large areas of inland New South Wales and Queensland are experiencing significant deficiencies at the shorter 3-month timescale, which are masked at the 4-month timescale due to above average rainfall during March along the eastern seaboard.
4-month rainfall deficiencies
Compared to the 3-month period ending May 2017, rainfall deficiencies have increased in both areal extent and severity along the west coast of Western Australia, with a large area around the Gascoyne coast, and smaller areas in the Central West and South West districts, observing lowest on record rainfall for similar March to June periods.
Rainfall deficiencies have also worsened on the Eyre Peninsula in South Australia, and have emerged on the Yorke and Fleurieu peninsulas, parts of the Adelaide region and the mid-North, and on Kangaroo Island; have emerged in West Gippsland and adjacent parts of northeastern Victoria; and have increased in Tasmania, now also affecting the west more broadly and the south of Tasmania.
Soil moisture in the lower layer (from 10 cm to 100 cm deep) decreased for June compared to May across most of Australia. The only areas to observe significant increases in lower layer soil moisture during the month were across the base of Cape York Peninsula, as rainfall received during May infiltrated the deeper soil.
Soil moisture for June was below average for the west and south of Western Australia; most of southern South Australia, except the far southeast; areas of western and southern Tasmania; eastern Victoria; areas of inland eastern and northern New South Wales; most of Queensland away from the east coast and Cape York Peninsula; the southern half of the Northern Territory and adjacent far northern South Australia.
Soil moisture for the month was above average for the Top End of the Northern Territory; the south of the Cape York Peninsula and Central Coast in Queensland; an area in northeastern New South Wales; scattered areas in inland Western Australia, near Derby in the Kimberley, and in central South Australia; and parts of far southeastern South Australia, the western half of Victoria, and adjacent parts of southwestern New South Wales.
- June rainfall below average for most of Australia, and the driest on record for large areas of southern Australia
- Serious to severe rainfall deficiencies are present at the 4-month timescale near the west coast of Western Australia, between the Eyre Peninsula and Adelaide region in South Australia, in western and southern Tasmania, and in West Gippsland in Victoria
- Soil moisture is below average across the west and south of Western Australia, most of southern South Australia, the southern half of the Northern Territory and far northern South Australia, much of inland Queensland and inland New South Wales, eastern Victoria, and parts of Tasmania
Product code: IDCKGD0AR0