Australian Seasonal Climate Summary: Winter 2009 (June-August)
Wednesday 2 September, 2009
Winter 2009 was exceptionally mild over much of Australia. Average maximum temperatures over the continent were the highest on record, while seasonal mean temperatures fell only just short of the 1996 record. It was also a rather dry season over much of the continent, particularly the north and east.
Maximum temperatures averaged over Australia for winter were 1.64°C above the long-term average, well above the previous record of +1.41°C set in 2002. Queensland (+2.33) and the Northern Territory (+2.04) also set records, by more than a degree in Queensland’s case. All other states also ranked in the top ten, with South Australia and New South Wales second, and Victoria third. Overnight minimum temperatures (1.02°C above average) were less extreme, but still ranked as the fifth-highest on record, with state records being set in South Australia (+1.83°C) and Tasmania (+1.42°C). Combining maximum and minimum temperatures, the seasonal mean was 1.33°C above average, just 0.01°C short of the record set in 1996, and state record winter mean temperatures were set in New South Wales, Victoria and South Australia.
Maximum temperatures were above average almost throughout Australia, except for a few small areas scattered through the southwest of Western Australia (especially the south coast) and in the northeast Victorian highlands. They were at least 1°C above average over most of mainland Australia, except in the southwest, and in Victoria and southeastern South Australia, and were 2−3°C above average over a large area encompassing the southern half of the Northern Territory and the southern half of Queensland away from the coast, as well as northeastern South Australia and northeastern new South Wales. Record high values covered a large area, including the Northern Territory away from the Top End, Queensland except for the southeast corner and Cape York Peninsula, and northeastern New South Wales, as well as southeastern coastal areas between Nowra and Melbourne.
Winter minimum temperatures were below average, mostly by less than 1°C, in parts of the northern tropics (especially in Queensland and the Northern Territory), as well as around Perth and on the Mid-North Coast of New South Wales. Elsewhere they were above average. They were at least 1°C above average over an area encompassing most of South Australia except for some coastal areas, the southern Northern Territory, southwest Queensland, eastern border areas of Western Australia, and southern and western New South Wales, and were also similarly high in most of Tasmania. In parts of the central continent anomalies reached 2−3°C. Records were set in most of Tasmania except the far south, and along the Nullabor and Eyre Peninsula coast between Port Lincoln and Balladonia, as well as locally in New South Wales.
*Fractional ranks denote tied values. **Anomaly is the departure from the long-term average.
It was a generally dry season away from the south coast, with Australian winter rainfall 25% below average (27th lowest of 110 years). Northern and eastern areas were especially dry, with the Northern Territory (which is normally dry at this time of year) 84% below average and Queensland 64% below. Rainfall totals were in the lowest decile along the Queensland coast between Cooktown and Bundaberg, and extending inland along the Flinders Highway corridor from Townsville to Mount Isa. Most of far western Queensland, the Northern Territory, northeastern South Australia and the north of Western Australia received little or no rain for the season. There were also areas in the lowest decile on the NSW-Queensland border around Goondiwindi, and on the NSW South Coast around Nowra.
In contrast, it was a very wet winter in Tasmania, ranking as the fourth-wettest on record (46% above average). Records were set on parts of the east coast between Swansea and Bruny Island. Most areas south of a St. Helens-Queenstown line were in the highest decile, as were parts of the northwest and Flinders Island. Whilst no part of the mainland was comparably wet, winter rainfall did match or exceed seasonal averages over most agricultural areas of South Australia, much of the western half of Victoria, and southwestern Western Australia west of a Geraldton-Bremer Bay line, as well as locally on the Mid-North Coast of New South Wales and around Charleville in Queensland.
*Fractional ranks denote tied values.
**A new area-averaging method has been adopted for rainfall from May 2009. Current and historical totals for Tasmania are substantially higher than under the old scheme, but differences for other states, and nationally, are negligible.