Australia's warmest 12-month period on record

September 2012 to August 2013: the last 12 months

The past 12 months have been the warmest on record for Australia. The average temperature across Australia for the period 1 September 2012 to 31 August 2013 was 22.92 °C. This is 1.11 °C above the 1961–1990 average, surpassing the previous record of +1.08 °C that occurred between February 2005 and January 2006.

Temperatures for the calendar year to date (January to August) are also the warmest on record, at 1.13 °C above the long-term average, exceeding the figure set in August 2005, which was Australia’s warmest calendar year on record.

The record 12-month period has been characterised by widespread heat across Australia. The average temperature has been above average over the entire continent, with no region registering below-average temperatures.

September 2012–August 2013 mean temperature deciles for Australia showing temperatures have been above average, to record warm over the entirety of Australia.

September 2012–August 2013 mean temperature deciles for Australia showing temperatures have been above average, to record warm over the entirety of Australia.

In the past 12-month period a large number of temperature records have fallen across Australia including:

  • Australia’s hottest summer day on record (7 January)
  • Australia’s warmest winter day on record (31 August)
  • Australia’s hottest month on record (January)
  • Australia’s hottest summer on record
  • Australia’s hottest January to August period on record
  • Australia’s warmest 12-month period on record

The period ending August 2013 has also resulted in numerous State and Territory records including:

  • The hottest January to August period on record for South Australia and Victoria
  • The warmest winter on record for Victoria
  • The warmest 12-month period on record for South Australia
  • The warmest winter day on record for the Northern Territory

Generally above-average temperatures have persisted with few breaks during the past 12 months, with long periods of warmer-than-average days and a distinct lack of strong cold fronts across the south. Nights have also been warmer than average, but less so than daytime temperatures.

Every calendar month since September 2012 has recorded temperatures 0.5 °C or more above average, with seven of those twelve months topping 1.0 °C above average including January, April, May, July and August of 2013. The warmth has extended to the oceans around Australia with widespread record warmth.

Monthly mean temperature anomalies for September 2012 to August 2013

Monthly mean temperature anomalies for September 2012 to August 2013.

The Remainder of 2013

If a mean temperature of more than 1.0 °C above average is maintained over the next one-, two-, three- or four-month periods, each of the 12-month periods ending September, October, November and December would exceed the previous record from 2005–06 for the warmest 12-month period.

The Bureau’s seasonal outlook for spring indicates that both maximum and minimum temperatures are likely to be above average over much of Australia. The outlook for warmer-than-average temperatures over the remainder of the year is consistent with the Bureau’s knowledge of background temperature trends, and the well-above-average water temperatures that currently surround Australia. Australian temperatures are now on average more than 1 °C warmer than during the 1950s.

Running means for Australian temperature anomalies for 12-month periods ending 31 August 2013. Vertical grid lines mark 12-month periods commencing January 1920, January 1930, etc. Australian temperatures are now on average more than 1 °C warmer than during the 1950s.

Running means for Australian temperature anomalies for 12-month periods ending 31 August 2013. Vertical grid lines mark 12-month periods commencing January 1920, January 1930, etc.