Rainfall Deficiencies

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.

Issued on 2 May 2013 by the National Climate Centre

Rainfall deficiencies continue and worsen in the southeast for shorter timescales

April rainfall was below average for most of Victoria and New South Wales, Tasmania, central Australia and southwestern Western Australia. Above-average April rainfall was recorded along parts of coastal South Australia and in the tropical north.

Most of New South Wales west of the Great Dividing Range recorded little or no rainfall for the month while central Victoria and parts of western Victoria also recorded April totals in the lowest 10% of records, bringing little relief from deficiencies across the southeast at either shorter or longer timescales.

Southeastern Australia continues to experience severe deficiencies at the 7-month (October 2012 to April 2013) timescale, although the focus of these deficiencies has shifted into Victoria and Tasmania, and now include substantial regions of lowest-on-record rainfall in agricultural regions (see 7-month deciles map).

Rainfall deficiencies at the 9-month (August 2012 to April 2013) timescale have worsened across most of Queensland and New South Wales west of the Great Dividing Range, when compared to the previous 8-month period. Rainfall totals for the period were in the lowest 10% of records for 26% of Queensland, with one third of the State drought declared by State Government.

Areas of serious to severe (lowest 10 and 5% of records) affect central, western and Riverina districts of New South Wales and southern Queensland between roughly Bollon and Charleville. Serious and severe deficiencies remain similar in the Gulf Country of Queensland while worsening in the far west of that State (see 9-month deciles map).

Severe rainfall deficiencies for the 9-month period have contracted across coastal South Australia. The area of western Victoria experiencing severe deficiencies (lowest 5% of records) has expanded compared to the 8-month period and now covers most of the western half of the State, as well as the southeastern corner of South Australia. Small areas of lowest-on-record totals for the period persist in the Mallee in northwest Victoria.

Longer-term rainfall deficiencies for the 13-month (April 2012 to April 2013) period remain largely unchanged over South Australia and adjacent areas of Western Australia.

Deficiencies extending from southeast South Australia through southern New South Wales have expanded slightly, taking in more of the Riverina and also increasing in Victoria to cover the southwest and central north as well as the northwest.

Scattered areas of serious to severe deficiencies remain over the remainder of inland New South Wales and Queensland and the southern Northern Territory. The small area of severe deficiencies on the southwest of the Cape York Peninsula has expanded compared to the pervious 12-month period.

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For more information about this rainfall deficiencies statement, please contact the following climatologists:
Darren Ray (SA) (08) 8366 2664
Aaron Coutts-Smith (NSW) (02) 9296 1525
Karl Braganza (National) (03) 9669 4344

A mob of sheep raises dust north of Dubbo, New South Wales, during drought. Photo by Department of Foreign Affairs and Trade

Subscriptions & Further Information

To subscribe to email alerts, contact helpdesk.climate@bom.gov.au and include 'Drought Statements' in the subject line.

Definitions

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 Update

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.

Seasonal Rainfall Outlooks

Current map, small viewSeasonal rainfall outlooks outline likely conditions over three-month periods.
Regional outlooks: northern Australia, south-eastern Australia, Western Australia.
Previous outlooks: Archive

Seasonal Temperature Outlooks

Current map, small viewSeasonal temperature outlooks outline likely conditions over three-month periods.
Regional outlooks: northern Australia, south-eastern Australia, Western Australia.
Previous outlooks: Archive

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.

Rainfall averages, variability & 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.

Drought Declarations & Assistance

Formal drought declarations are handled by State or Federal Government.
Further details

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'