Australian Monthly Climate Summary: July 2008
Monday 4 August, 2008
Temperatures and rainfall were relatively close to normal through large parts of Australia in July. Averaged over the continent, daytime maximum temperatures were somewhat above-normal, whilst rainfall and minimum temperatures were very close to normal.
Daytime maximum temperatures were above normal over most of Australia (national anomaly +0.78°C, 13th highest of 59 years). All states saw above-normal maxima (although Victoria and Tasmania were very close to normal), but the Northern Territory (+1.23°C, 10th) was the only region to rank in the top 10.
The warmest days were found in west-central Australia, with mean monthly maxima in the highest decile in the eastern interior of Western Australia, the south-western Northern Territory and the far northwest of South Australia. Over this region mean maxima were generally 2−3°C above normal and a few July daily records were set towards the end of the month. In contrast, maximum temperatures were slightly below normal over much of Victoria and Tasmania, the southern half of South Australia, southern coastal Western Australia, the Kimberley region and eastern Queensland, but only on the north tropical coast did they locally reach 1°C or more below normal, and nowhere was in the lowest decile.
Minimum temperatures were close to normal over much of the country, with a national anomaly of −0.01°C (26th lowest of 59 years). The largest departures from normal were in the north of Western Australia and the north-western Northern Territory, where minima were generally 1−3°C below normal and reached the lowest decile. Other areas where minimum temperatures were significantly below normal, although only by about a degree, were east Gippsland and southern Tasmania, with Tasmania’s statewide anomaly (−0.64°C) being the tenth-lowest on record. The only substantial area with minima 1°C or more above normal was south-eastern Queensland, with other areas being close to normal.
* Anomaly is the difference from the long-term average
Rainfall averaged over the continent was 4% below the long-term (1961−90) mean. There were two major areas of above-normal rainfall. The most significant of these was in eastern Queensland where an unseasonable rain event affected the eastern tropics and subtropics. Most of the region received 50−150 millimetres in the week ending 28 July. As July is close to the peak of the dry season in the tropics, these rains were sufficient to put rainfall into the highest decile over much of eastern Queensland, with July records set over a broad band inland from the tropical coast between Cairns and Mackay. Queensland’s statewide average for the month was 95% above normal.
The other substantial area of above-normal rainfall was the southwest of Western Australia south of a Shark Bay-Kalgoorlie-Eucla line, although anomalies there were smaller with only a few localities reaching the highest decile. The southwestern WA regional average was 17% above normal. Above-normal rains also fell along the NSW coast from Newcastle northwards.
Away from eastern and central Queensland, the tropics and central Australia were seasonally dry, with no rain falling in most of the Northern Territory and adjacent far western Queensland, the northern half of Western Australia, and north-eastern South Australia. Victoria, New South Wales and the southern half of South Australia mostly saw near- to slightly below-normal rainfall, while Tasmania was somewhat drier than normal throughout (statewide anomaly −28%).