September 2018 Australia’s driest September on record

Last month was Australia's driest September on record, the Australian Bureau of Meteorology reported October 1, 2018. Nights were much cooler than average for the time of year over much of Victoria, South Australia and southern New South Wales.

September was an exceptionally dry month, especially across the southern mainland. Rainfall was the lowest on record for September both nationally, and for southern Australia (i.e. those areas south of 26°S). It was the second driest September on record for Victoria, third driest for Western Australia, and fourth driest for South Australia.

Rainfall totals were in the lowest 10% of historical rainfall totals for the month in large areas including greater southwestern Western Australia (southwest of a line between about Geraldton and Esperance), South Australia from Ceduna east across the Eyre Peninsula and agricultural districts, much of the western half of New South Wales, and nearly all of Victoria except parts of South and West Gippsland. 

Rank ranges from 1 (lowest) to 119 (highest). A rank marked with ’=‘ indicates the value is tied for that rank. Departure from mean is relative to the long-term (1961–1990) average.

September rainfall was below average across most of the remainder of southern Australia, Queensland and the Northern Territory, but near average for large parts of northeastern New South Wales and large areas of southeastern to Central Coast Queensland.

Total rainfall for the month was the lowest on record for September at many sites in Victoria and Western Australia, and a handful of locations in New South Wales and Tasmania. The year to date has also been exceptionally dry over the mainland southeast, with significant rainfall deficiencies continuing to affect large areas of eastern Australia at timescales out to around two years duration.

Above average rainfall was only recorded in small pockets, including northeastern New South Wales, parts of the coastal Kimberley, and about Joseph Bonaparte Gulf with very much above average rainfall in part of the southwestern Top End due to unseasonable rainfall in the last week of the month.

Featured image credit: JMA/Himawari-8, RAMMB/CIRA. Acquired: October 2, 2018