Issued 4 September 2006

Rainfall deficiencies spread following record dry August

Averaged across Australia, August 2006 was the driest August in the historical record from 1900, as well as being the warmest since high-quality monthly temperature records began in 1950. As a result, rainfall deficiencies expanded over southern Australia with record low winter falls over a large part of southern WA and parts of southeastern Australia. Deficits dating from the start of autumn intensified across the southeast, including Tasmania.

3-month rainfall deficiencies

For the 3-month period from June to August (winter), generally severe rainfall deficiencies covered most of the area south of a line from Exmouth (WA) to Eucla (WA) to Port Augusta (SA) to Albury (NSW) to Canberra (ACT) to Sale (Vic), as well as northern, central and eastern Tasmania. Record low winter totals occurred over an extensive area within the Perth/Esperance/Exmouth triangle, as well as in smaller patches in southeast SA, southern and western Victoria, and northern and southeast Tasmania. Multi-year rainfall deficits in the southeast, have been exacerbated by the most recent period of suppressed rainfall.

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Black and white | High resolution colour

6-month rainfall deficiencies

For the 6-month period from March to August (autumn-winter), serious to severe rainfall deficiencies extend in a band from southeast SA to central Victoria to the central-west of NSW, where record low falls have occurred. An area near Albury and another region on the SA/Vic border have also had their driest autumn-winter on record. The zone from north of Carnarvon to Albany in western WA is also affected, with areas of lowest on record falls along the coast. August rainfall in southwest WA was sufficient to ease the deficits, with much less of the area having record low rainfall than was evident at the end of July.

Deficits expanded over Tasmania for this period, with record low falls on the north coast, but there was little change to the pattern of deficiencies in southeast Queensland.

Click on the map for larger view

Click on the map for larger view
Black and white | High resolution colour

Deficiencies for the period dating from January will no longer be monitored as they are essentially covered by the three and six month periods.

Rainfall deficiency maps for longer periods indicate that deficiencies at the three year timescale, which are particularly relevant to water supplies, remain prevalent in parts of eastern Australia, especially in Queensland.

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.

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