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 in Hopetoun, Victoria, a record for the state that stood until 2026. Many locations through the region recorded all-time high temperatures including capital cities Adelaide, which reached its third-highest temperature,, and Melbourne, which recorded its highest-ever temperature on record,. Both cities broke records for the most consecutive days over, while Mildura, Victoria recorded an all-time record twelve consecutive days over.
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. Higher temperatures returned on the following weekend with Melbourne recording its hottest day since records began in 1855,.
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.

Cause

The heat wave was caused by a slow-moving high-pressure system that settled over the Tasman Sea. Coupled with an intense tropical low and a monsoon trough over Northern Australia, this produced hot, tropical air to be directed over southeastern Australia, raising temperatures significantly. The CSIRO stated that "The warm lower tropospheric anticyclone is the key synoptic weather system responsible for the heat-waves." The heat wave was the worst in Australia's history.

Records and statistics

During the heat wave, several records were broken; Tasmania recorded its highest-ever temperature; in Scamander, and the long-standing Tasmanian record of was broken five times within two days at Flinders Island, Fingal, St Helens and Scamander, while Hopetoun in Victoria recorded the highest temperature of the heat wave,, which was a state record until 2026.

Adelaide, South Australia

  • Average daily maximum 27 January – 7 February: –
  • 13 Consecutive days over
  • 6 Consecutive days over
  • 4 Consecutive days over

    Melbourne, Victoria

  • Average daily maximum 27 January – 7 February: –
  • 12 Consecutive days over
  • 5 Consecutive days over
  • 3 Consecutive days over

    Mildura, Victoria

  • 12 Consecutive days over
  • 5 Consecutive days over

    Wagga Wagga, New South Wales

  • 14 Consecutive days over
  • 13 Consecutive days over
  • 4 Consecutive days over

    Temperatures (daily maximum)

Avalon">Avalon, Victoria">Avalon, Victoria">Victoria (Australia)">Victoria

January 2009
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February
January 2009
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February
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    Mildura">Mildura, Victoria">Mildura, Victoria

January 2009
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February
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  • 7th – – 12th consecutive day over 40 °C
  • 8th –

    Deniliquin">Deniliquin, New South Wales">Deniliquin, [New South Wales]

January 2009
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February
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    Swan Hill">Swan Hill, Victoria">Swan Hill, Victoria

January 2009
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February
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    [Melbourne], Victoria

Temperatures have been recorded since 1855.
January 2009
  • 27th –
  • 28th –
  • 29th –
  • 30th – – Third-hottest day recorded in Melbourne.
  • 31st –
February
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  • 7th – – Hottest day recorded in Melbourne 0.8 °C hotter than previous record.

    [Adelaide], South Australia

January 2009
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February
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A record-high minimum temperature was recorded at around midnight on 29 January, when the temperature dropped to only at the Bureau of Meteorology weather station in Kent Town, near the Adelaide city centre. Temperatures recorded in other parts of the city and other towns throughout South Australia were even higher.

Woomera">Woomera, South Australia">Woomera, South Australia

January 2009
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February
January 2009
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February
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  • 7th – – Hottest day recorded in Wagga Wagga since records began in 1941.
  • 8th –
On 31 January 2009, Wagga Wagga broke the all-time January record for the most days above with six days recorded. The January record set in 1979 was equalled for number of days above or more which is 19 days.
Wagga Wagga broke the all-time record and the February record for the highest recorded maximum on 7 February 2009, 2:50pm AEDT the city recorded with the previous February record being set on 1 February 1968 and the all time previously being set on 23 January 2001.
On 8 February 2009, the record for the consecutive days over was to be broken with thirteen consecutive days recorded. Wagga Wagga also recorded fourteen consecutive days of over.

Albury">Albury, New South Wales">Albury–Wodonga">Wodonga, Victoria">Wodonga, NSW/VIC

January 2009
  • 26th –
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February
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  • 7th – – Hottest day recorded in Albury–Wodonga since records began in 1973.
  • 8th –

    Ballarat">Ballarat, Victoria">Ballarat, Victoria">Victoria (Australia)">Victoria

January 2009
  • 28th –
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February
January 2009
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February
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    Launceston">Launceston, Tasmania">Launceston, [Tasmania]

January 2009
  • 28th –
  • 29th –
  • 30th – – Hottest day recorded in Launceston since records began in 1980.
  • 31st –

    Accompanying bushfires

After a slow start to the 2008–09 Australian bushfire season, the high temperatures and wind precipitated several bushfires across Victoria and South Australia. The conditions were very similar to the heat wave experienced in early January 1939, which killed 438 people and precipitated the Black Friday bushfires of 1939.
Fires were also started in the Australian Alps by lightning strikes from dry thunderstorms in north-east Victoria and south-east New South Wales.
The tail end of the heat wave also precipitated the Black Saturday bushfires, in which 173 people died, 414 injured and 2,029 houses destroyed at various locations across the state. Several locations around the state recorded their highest temperatures since records began in 1859 and winds gusted up to 110 km/h.

Comparison to normal climate for the area

Many areas in central South Australia, northern Victoria and inland New South Wales regularly experience temperatures over for one, two or three consecutive days, sometimes more, during the summer months. During the heat wave, however, many of these regions experienced temperatures over for twice as long or more, on average, than is normal for that time of year. Coastal regions and the ACT experienced slightly lower temperatures; however, these were still above average and lasted for a prolonged period.
While coastal regions may have experienced shorter periods of heat wave, for the time that they did experience temperatures over, they mostly reached the top 3, top 5 or top 10 all-time temperature records for a number of days.
The heat wave was perhaps most extreme in northern and eastern Tasmania, where 7 of the 8 highest temperatures recorded in Tasmania up to that time occurred during the heat wave.
A chart of the variation of maximum and minimum daily temperatures, through the year, for Melbourne was prepared from observations between May 1855 and August 2006. For early February, this shows a mean daily maximum temperature of with the 75th-percentile temperature being about.