Australian Monthly Climate Summary: March 2008
Thursday 3 April, 2008
March 2008 was notable for an exceptional prolonged heatwave which affected much of southern Australia during the first three weeks of the month. Widespread below-normal temperatures at the end of the month limited the number of monthly records which were set, but it was still a very warm month over southern parts of the country. It was also rather dry over most of Australia, although some areas received useful rain at the end of the month to bring monthly totals near average.
The heatwave affected much of southern Australia, with its peak between 3 and 17 March. South Australia saw the most extreme heat, but there were also many extremes in Victoria, the south-east of Western Australia and parts of Tasmania. Adelaide experienced 15 consecutive days above 35°C, and 13 consecutive days above 37.8°C (100°F), both far in excess of the previous records of 8 and 7 days respectively. Many other locations also set records for consecutive days above thresholds. The heatwave was more exceptional for its length than its intensity, with relatively few locations setting monthly records for March, although Hobart (37.3°C) equalled its March record high temperature on the 14th, and Campania (38.0°C) setting a state record for March on the same day.
Averaged over Australia, maximum temperatures for the month were 0.79°C above the 1961−90 average (16th highest on record). Maxima were 3−5°C above average over an area covering most of South Australia south of the Indian-Pacific railway line, Victoria west of Melbourne, and the far south-east of Western Australia. Most of this area experienced its warmest March of the post−1950 period. Outside this area, it was 1°C or more above normal over the remainder of Victoria, almost all of Tasmania and South Australia, the southern and western inland of New South Wales, and most of interior and south-western Western Australia. In contrast, monthly mean maxima were below normal over most of Queensland except for the far west and north, coastal Western Australia north of Carnarvon, and the north-east of the Northern Territory. Anomalies were below −1°C in the Pilbara and much of eastern Queensland, locally reaching −2°C around Cooktown and Roma.
Averaged over Australia, minimum temperatures for the month were 0.05°C above the 1961−90 average (27th highest on record). Minimum temperatures were above normal in most of Western Australia (except the far north), the Northern Territory, South Australia, and Victoria (except near Melbourne), as well as in south- western New South Wales and north-eastern Tasmania. Anomalies were weaker than for maxima, with scattered patches in the +1−2°C range through much of the areas, particularly in the southern half of Western Australia and agricultural areas of South Australia. Most other areas had cool nights, particularly in Queensland and northern New South Wales. The last few days of the month were particularly cold, with site records set at many locations in southern Queensland and north-eastern New South Wales, and Stanthorpe (−0.2°C on the 30th) experiencing the first sub-zero March temperature recorded in Queensland.
* Anomaly is the difference from the long-term average
Rainfall was below normal over the bulk of the continent, although not exceptionally so, with significant rain events occurring in the south-west and the south-east in the closing days of the month after little or no rain in the first three weeks. All state and territory means were below normal (ranging from 19% below in Western Australia to 83% below in South Australia), but none ranked in the driest 20 Marches of the post−1900 period. The Australian average was 44% below normal, ranking 22nd lowest of 109 years.
The only areas of any size which saw above-normal rainfall were the Pilbara and Gascoyne regions of Western Australia, the east coast of northern Queensland north of Cardwell, and parts of the Northern Territory Top End and Gulf coast. More isolated above-normal falls occurred in northern inland New South Wales and around Melbourne. The only substantial area in the highest decile was the west coast between Shark Bay and Karratha. Most of the rest of the country saw below- normal rainfall, but only relatively limited areas were in the lowest decile, the most extensive being a band extending from north-eastern New South Wales northwest across inland Queensland to the Mount Isa area.