Australian Seasonal Climate Summary: Winter 2008 (June-August)
Monday 1 September, 2008
Both temperatures and rainfall were close to normal over most of the Australian continent in winter, with a mild June being offset by a cool August. Relatively few areas departed strongly from the long-term average in either direction, although there was a tendency towards dry conditions in the southern half of the continent.
Both daytime and overnight temperatures were close to normal across most of the continent. National maximum temperatures were 0.32°C above the long-term average (27th highest in the 1950−2008 period). All states and territories were above the long-term average, although only Tasmania (+0.61°C, 10th highest) ranked in the top 20, and whilst Victoria’s mean maxima (anomaly +0.22°C) were above the long-term average, they were still the lowest since 1998. Maxima were within 1°C of average almost across the continent, with a leaning towards above-average conditions in the west. The only areas which were more than 1°C above average were around Shark Bay and Broome in WA, and Moree in NSW, and the highest decile was reached only on the north coast of the Northern Territory and on Flinders Island. No areas were in the lowest decile.
Overnight minimum temperatures were even closer to the long-term average, with the national average, 0.03°C below average, ranking as the 26th lowest in the 1950−2008 period. No state or territory ranked in the top or bottom 10. The most substantial areas of below-normal minima were in the north-west of the continent, reaching 1−2°C below normal in much of the Kimberley. Similar anomalies also occurred further south around Carnarvon, which along with the Albany area reached the lowest decile, the only part of Australia to do so. Anomalies of +1°C occurred locally around Kalgoorlie and Canberra, but most of southern and eastern Australia were within 1°C of the long-term average.
* Anomaly is the difference from the long-term average
Australian area-averaged rainfall for winter was 11% below the long-term (1961−90) average, ranking 41st lowest out of 109 years. It was wetter than normal over large parts of northern Australia, especially in Queensland (except for the far north-west and parts of the southern inland), and was also wetter than normal in a band extending from the eastern Kimberley south-east across the southern Northern Territory into the far south-west of Queensland. However, winter is the peak of the dry season in most of these regions and most of the rain came in a small number of events. Only in eastern Queensland, where a system in late July saw falls over a week widely in the 100−200 millimetre range, were substantial amounts involved over a large area.
Rainfall was slightly below normal over most of the southern half of Australia. The only substantial areas with above-normal rainfall were around Adelaide, and in the Hunter and Mid-North Coast regions of New South Wales. However, falls in the lowest decile were rare, with the only substantial areas of such conditions occurring along the south coast of Western Australia and in north-eastern Tasmania. No state was more than 25% below the long-term average, and only Tasmania (17th) ranked in the driest 20 winters since 1900.