Australian Monthly Climate Summary: October 2007
Friday 2nd November, 2007
October was another warm and generally dry month over most of Australia. Mean temperatures for the month (anomaly +1.29°C) were the sixth-highest on record, whilst daytime maximum temperatures (+1.67°C, 7th) and overnight minimum temperatures (+0.92°C, 9th) also ranked in the top ten. Despite scattered falls in the last week of the month, rainfall was generally below average, with a national mean 36% below normal.
Daytime maximum temperatures were above normal almost throughout the continent. The only areas with below-normal values were the south coast of Western Australia, western Tasmania, and a few patches along the tropical coast. NSW was especially warm; although records were set only in a small area around Moree, almost all of the state was in the highest decile, with anomalies of +3 to +4°C widespread in the eastern half of the state. The state-wide anomaly (+3.16°C) was second only to October 2006.
Warm conditions, with mean maximum temperatures mostly 2−3°C above normal and in the highest decile, also covered northern Victoria, Queensland south and west of a line from Brisbane to Mount Isa, northern SA, and the south and east of the Northern Territory.
Anomalies of overnight minimum temperatures were generally less pronounced than those of daily maxima, but were still significant in many parts of the country. Minima were in the highest decile in most of extra-tropical Queensland and north-eastern South Australia, as well as in areas around Canberra, in south-western NSW, and in the far east of Victoria. Monthly anomalies in these areas were generally +1 to +2°C, reaching +3°C locally in southern inland Queensland.
In contrast, minima were below normal in most of Tasmania, western Victoria and southern SA, the far south-west of WA, and most of the far north of that state. Around Derby anomalies reached −2°C with some records being set, whilst mean minima in the lowest decile, with anomalies around −1°C, also occurred in the Wimmera in western Victoria.
* Anomaly is the difference from the long-term average
The most notable dry conditions occurred in Victoria, where October was the 7th driest on record (64% below normal), the third very dry month in succession. Rainfall was in the lowest decile in much of central and north-western Victoria, with Kerang remaining rainless. There were also areas of rainfall in the lowest decile in south-western New South Wales, a strip through the Central Tablelands and Central West Slopes of NSW, parts of the mid-west of WA, some areas of north-eastern SA (which had no rain for the month) and a small area in north-central Tasmania.
The only substantial areas of above-normal rainfall were the south-west of WA, western Tasmania, and south-eastern Queensland away from the immediate coastal strip. Above-normal falls were also scattered through tropical Queensland and the NT, as well as in the mid-north of SA and the northern border of New South Wales, mostly associated with localised thunderstorms. A few locations particularly favoured by thunderstorms reached the highest decile, as did parts of south-western Tasmania.