Australian climate information

Australia’s climate has warmed since national records began in 1910, especially since 1950. The warming trend occurs against a background of year-to-year climate variability, mostly associated with El Nino and La Nina in the tropical Pacific.

The CSIRO 2014 State of the Climate report states that for Australia:

  • Mean sea surface temperature has increased by 0.9oC since 1910

  • Since 2001, the number of extreme heat records in Australia has outnumbered extreme cool records by almost 3 to 1 for daytime maximum temperatures, and almost 5 to 1 for night-time minimum temperatures

  • The duration, frequency and intensity of heatwaves have increased across large parts of the country since 1950

  • Rainfall averaged across the country has slightly increased since 1900, with a large increase in north-west Australia since 1970. A declining trend in winter rainfall persists in south-west Australia. Autumn and early winter rainfall has mostly been below average in the south-east since 1990.

Regional climate change attribution studies have shown significant consistency between observed increases in Australian temperatures and those from climate models forced with increasing greenhouse gases. A study of the 2012-13 record hot summer found that the odds of this event occurring were found to have increased five-fold due to human influences.

Attributing observed regional rainfall changes is a more difficult task than attributing temperature changes. This is especially so in Australia, where intrinsic rainfall variability year-on-year and decade-to-decade timescales is large. However, literature to date seems to indicate that drying across Australia cannot be explained by natural variability alone. For example, warming reduces the temperature gradient between the equator and pole, reducing the energy available to mid-latitude weather systems.

Climate change projections show how Australia’s climate may change in the future, using up to 40 existing global climate models. The projections indicate that continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system (see figure below). For more specific regional projections see Climate Change in Australia – Projections for Australia’s NRM Regions

Caption: Changes in the global climate system. Source: State of the Climate 2014.


References