Rainfall deficiencies

A mob of sheep raises dust north of Dubbo, New South Wales, during drought. Photo by Department of Foreign Affairs and Trade Australia is a large continent containing many different climate zones, from wet tropics in the north, arid and semi-arid conditions in the interior, and alpine climates in the south-east. Each climate zone is influenced by very different large-scale, predominant weather and climate patterns. For this reason, at any time different parts of the Australian continent can be affected by very different climate extremes. An example of this occurred in 2010, where southwest Western Australia experienced its driest year on record, in contrast to the rest of Australia, which received above-average to very-much-above-average rainfall.

Use our Drought Statement, rainfall maps and reports to watch for areas with significant long and short-term rainfall deficiencies.

Updated on 3 June 2015

Victorian situation worsens

May rainfall was below average for most of northern Australia except the Top End, the south of Western Australia, southern New South Wales and parts of northern and eastern Victoria, as well as an area of South Australia around and inland of Ceduna and other smaller pockets. Rainfall was above average roughly following the path of a northwest cloudband extending from the Pilbara into the interior and northern South Australia, where moderate falls brought some relief of deficiencies. Northwestern New South Wales, much of Tasmania, a region of the east coast in northern New South Wales and southeastern Queensland, and the Top End also received above-average rainfall.

Monthly rainfall over the southeast of South Australia through western Victoria, and across western Tasmania has been below average from August last year (apart from well-above-average January rainfall, and above-average March and May rainfall in Tasmania). Serious or severe rainfall deficiencies have been observed in parts of these regions for various medium-term periods since late 2013. Longer-term deficiencies are also evident for various periods under 2 years duration in much of this region, and deficiencies are also evident over large areas of eastern Australia for periods of about 3 years duration.

11-month rainfall deficiencies

Above-average rainfall during May has alleviated deficiencies in northern parts of South Australia and along the west coast of Tasmania, although local deficiencies remain. Below-average May rainfall for an area of northern to central Victoria has seen deficiencies expand in this region, compared to the 10-month period in the previous Drought Statement. The spatial extent and severity of rainfall deficiencies has also increased slightly in central Queensland, whilst severe or serious deficiencies (lowest 5% or lowest 10% of records) persist with little change in coastal South Australia covering the central West Coast District of South Australia and the York and Fleurieu peninsulas, a region spanning southeastern South Australia and much of western to central Victoria, and areas of northern Queensland near Townsville, the central to western Cape York Peninsula, and along the southern coast of the Gulf of Carpentaria.

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Black and white | High resolution colour

32-month rainfall deficiencies

At the 32-month timescale (October 2012 to May 2015), the area affected by rainfall deficiencies has increased slightly in northern to central Victoria and increased in severity in central northern Queensland. Elsewhere, deficiencies remain similar to those for the preceding 31-month period.

Severe and serious deficiencies are in place in a broad area extending from south of the Cape York Peninsula, through central and western Queensland, into the areas of central southern Queensland and northern New South Wales inland of the Great Dividing Range. Deficiencies are also in place in an area covering western to central Victoria, extending into adjacent southeastern South Australia.

Deficiencies also persist at a range of even longer timescales, with most of eastern Australia having received below-average rainfall following the conclusion of the 2010–12 La Niña events.

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Black and white | High resolution colour

Soil moisture

Soil moisture in the upper layer for the week ending 24 May had increased in the southeast mainland and decreased in much of Western Australia and across Tasmania, compared to the week ending 26 April.

Upper layer soil moisture at the end of May was below to very much below average across most of the Northern Territory, the northern Kimberley, the eastern Cape York Peninsula in Queensland, extending south to about Townsville, and across central Australia and pastoral South Australia. Soil moisture was above average across the Pilbara and adjacent parts of Western Australia, southwest Western Australia, much of southern South Australia, coastal western Victoria, and large parts of the east coast between South Gippsland and southeastern Queensland.

Lower layer soil moisture for the week ending 24 May was higher across much of Western Australia than for the week ending 26 April, also increasing across most of southern South Australia, along the coast of New South Wales, and in Gippsland in Victoria. Lower layer soil moisture had decreased in large parts of Queensland, most of the Northern Territory, and the Kimberley.

Lower layer soil moisture was above average for most of Western Australia, the central to southern Northern Territory, a small area of eastern Queensland and pockets along the coast of New South Wales, eastern Victoria, much of the south of South Australia but not the southeast, and parts of Tasmania. Soil moisture was below average in Western Australia for the northern half of the South West Land Division, extending just into the Goldfields District; areas of coastal northern Queensland, inland central Queensland, and an area inland of the Great Dividing Range spanning the border between Queensland and New South Wales; parts of the Top End and along the coast of the Gulf of Carpentaria; a small areas of southern New South Wales, much of central to western Victoria and adjacent southeastern South Australia.

Further information

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Archives

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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

These maps are also available from Maps - recent conditions

Weekly rainfall updates

Current map, small viewThe Weekly Rainfall Update describes rainfall over the previous week. It includes a map and a summary table of the highest weekly totals. A discussion of the impact of recent rains on rainfall deficiencies is also presented.

Rainfall and temperature outlooks

Current map, small viewRainfall 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.
Rainfall and temperature outlooks: Outlooks
Previous outlooks: Archive of outlooks Archive of outlook maps

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.

Climate statements archive

The archive includes previous monthly, seasonal and annual climate summaries for nation-wide, state/territory and capital city conditions.

Maps of recent conditions

CSIRO water balance maps

Small image of water balance mapCSIRO (AWAP) Water balance maps include maps of soil moisture and water fluxes contributing to changes in soil moisture (rainfall, transpiration, soil evaporation, surface runoff and deep drainage).

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

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.

Acknowledgements

Front page photo, provided by Department of Foreign Affairs and Trade: 'A mob of sheep raises dust north of Dubbo, New South Wales, during drought'