Australian temperatures have increased during the past 100 years, especially since the 1950s. This increase has also been observed at the global level, and is associated with increasing concentrations of greenhouse gases in the atmosphere. The year 2015 was the warmest on record for the globe. The shift towards higher temperatures has been associated with regional increases in the frequency, duration and intensity of extreme heatwaves. The past few years have seen a number of these extreme heat events across Australia, with the record hot summer of 2012–13 having the warmest month, week and day on record. The year 2013 was Australia’s warmest year on record. Spring 2014 was Australia’s warmest spring on record, followed by spring 2015 and spring 2013.

Australian rainfall has been highly variable during the past 100 years, particularly in the past 40 years. The millennium drought began in 2000, and ended in 2010 with Australia’s 2-year period on record, which were associated with strong La Niña events in the tropical Pacific (La Niña events tend to result in above average rainfall for much of Australia). After that, drought re-emerged across large areas of southern and eastern Australia, including Queensland. Long-term rainfall deficiencies across Victoria, Tasmania, south-eastern South Australia and south-western Western Australia are overlaid on a long-term trend of declining rainfall in autumn and winter (the southern wet season) in parts of south-eastern and south-western Australia. The strong El Niño event of 2015–16 further reinforced these dry conditions across large parts of eastern Australia.