Rainfall deficiencies

Issued 4 August 2016

Continued reduction in rainfall deficiencies following a wet July

Rainfall during July 2016 was above to very much above average for most of Australia. In the south rainfall was below average for much of the South West Land Division, but generally above average for the remainder of Western Australia, and also above average for much of southeast Australia. For Queensland and Tasmania it was the seventh-wettest July on record, while for Victoria it was the tenth-wettest July.

The July rainfall has removed deficiencies for the period starting in May 2015 over parts of southeastern South Australia and Victoria, although small areas of deficiencies remain, especially in central southern Victoria.

15-month rainfall deficiencies

Very high July rainfall over much of southeast Australia has removed or significantly reduced deficiencies in southeast South Australia and western to central southern Victoria. Patches of serious to locally severe rainfall deficiency remain in some areas along the South Australia–Victoria border and in central southern Victoria between the Goldfields and South Gippsland where conditions have not been quite so wet.

Deficiencies in some areas of coastal Western Australia have increased following below average July rainfall for areas centred on the western Kimberley and South West Land Division.

Areas of deficiencies also persist in the Top End and at the tip of Cape York Peninsula where winter rainfall is climatological light and makes up a small part of the annual total.

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Longer-term deficits in many parts of the country

Since the most recent La Niña concluded in autumn 2012, rainfall was generally below average over large parts of Queensland and into northern New South Wales, and also over western Victoria, Tasmania and southwest Western Australia through to early 2016. Despite above average rainfall over large parts of eastern Australia in recent months, the accumulated rainfall deficits over the past four years are very large, and will require a great deal of rain to remove them. Seasonal conditions, such as temperature, may be more important as the limiting factor in the current winter–spring agricultural growing season.

Rainfall analyses for standard periods out to 48 months are available on our website.

Comprehensive reports on observed change in Australia's climate and regional climate change projections are available at the Climate Change in Australia website. The Bureau produces a number of long-term timeseries for monitoring Australia's climate, including rainfall and temperature.

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Soil moisture

Soil moisture in the lower layer (from 10 to 100 cm deep) has again increased over much of the country following widespread above average rainfall in July.

Soil moisture for July was above average over much of Australia, and very much above average for central Queensland to the western Cape York Peninsula, much of New South Wales and much of Tasmania. Soil moisture was also very much above average for large areas along a band from Western Australia's Pilbara, through central Australia, to smaller pockets across northern South Australia.

Below-average soil moisture is apparent in parts of southwest Western Australia and the Central Wheat Belt district, a small area of the western Kimberley near Derby, and parts of the central Top End. Generally average soil moisture surrounds these areas, extending across much of the South West Land Division and areas further inland in Western Australia, part of the Nullarbor, areas between the western Kimberley and northern Interior district, much of the north of the Northern Territory, southeast Queensland and coastal northeastern New South Wales, and western Tasmania.

Soil moisture information presented here is from the Bureau's operational Australian Water Resources Assessment Landscape (AWRA-L) model.

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Further information

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Product Code IDCKGD0AR0

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

The 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

AWRA-L water balance maps

Small image of water balance mapAustralian Water Resources Assessment Landscape 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 in the historical analysis, which runs from 1900.
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.