2009 southeastern Australia heat wave
The 2009 southeastern Australia heat wave was a heat wave that commenced in late January and led to record-breaking prolonged high temperatures in the region. The heat wave is considered one of the, if not the, most extreme in the region's history. During the heat wave, fifty separate locations set various records for consecutive, highest daytime and overnight temperatures. The highest temperature recorded during the heat wave was 48.8 °C (119.8 °F) in Hopetoun, Victoria, a record for the state. Many locations through the region recorded all-time high temperatures including capital cities Adelaide, which reached its third-highest temperature, 45.7 °C (114.3 °F), and Melbourne, which recorded its highest-ever temperature on record, 46.4 °C (115.5 °F). Both cities broke records for the most consecutive days over 40 °C (104 °F), while Mildura, Victoria recorded an all-time record twelve consecutive days over 43 °C (109 °F).
Approximate affected area shown in red | |
| Areas | South Australia, Victoria, Southern New South Wales, Northern Tasmania, ACT |
|---|---|
| Start date | 25 January 2009 |
| End date | 9 February 2009 |
| Peak temp. | 48.8 °C (119.8 °F), recorded at Hopetoun, Victoria |
| Losses | |
| Deaths | 374 |
| Injuries | 2,000+ |
The exceptional heat wave was caused by a slow-moving high-pressure system that settled over the Tasman Sea, with a combination of an intense tropical low located off the North West Australian coast and a monsoon trough over Northern Australia, which produced ideal conditions for hot tropical air to be directed down over southeastern Australia. The heat began in South Australia on 25 January but became more widespread over southeast Australia by 27 January. A weak cool change moved over the southern coastal areas bringing some relief on 30 January, including Melbourne, where the change arrived that evening, dropping temperatures to an average of 30.8 °C (87.4 °F). Higher temperatures returned on the following weekend with Melbourne recording its hottest day since records began in 1855, 46.4 °C (115.5 °F).
The heat wave generated extreme fire conditions during the peak of the 2008–09 Australian bushfire season, causing many bushfires in the affected region, contributing to the extreme bushfire conditions on 7 February, also known as the Black Saturday bushfires, which claimed 173 lives in Victoria.