Issued on 6 October 2009
Short-term rainfall deficits develop over eastern Australia and ease slightly over parts of southern and central Australia
A wetter than usual September over much of southern and central Australia has partially eased some of the short-term rainfall deficits that have existed in these regions since the start of 2009. In contrast, after a particularly dry July and August in eastern Australia, another month of generally drier than normal conditions this September has seen short-term severe deficits emerge on the three month scale. More information about Australia’s rainfall in September, and any other month can be found here.
3-month rainfall deficiencies
For the 3-month period from July to September 2009, serious to severe rainfall deficiencies are evident over large areas of Queensland and some parts of NSW. Some more areas of serious to severe rainfall deficits are evident in the NT and over northern WA. Although rainfall is climatologically low at this time of the year over northern Australia, Queensland was particularly dry during this period, experiencing its fifth driest July on record and fourth driest August. The NSW and Queensland cropping regions have suffered significant water and heat stress during this period.
9-month rainfall deficiencies
For the 9-month period from January to August 2009, serious to severe rainfall deficiencies remain evident over the south coast of NSW and over central and eastern Victoria. A few very isolated areas of serious to severe deficiencies also remain evident across central Australia and in southwest WA, near Lake Grace. Several sites in East Gippsland, in Victoria have recorded lowest on record rainfall for the period. Apart from the south coast of NSW and a region of central Australia near the SA, NSW and Queensland border, good September rainfall over much of southern and central Australia has resulted in a partial easing of the short-term deficits compared with those that existed for the 8-month period ending August 2009.
Rainfall deficiency maps for standard periods out to three years are available here.
Very long-term rainfall deficiencies outside of the drought periods discussed above persist across parts of southern and eastern Australia. Most notably, rainfall has been below average across much of southwest and southeast Australia since 1997, while the Murray-Darling Basin has experienced below average rainfall since 2002.
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.
Product Code IDCKGD0AR0