From late December 2012 to early January 2013, Australia experienced a nationwide heatwave. Temperatures peaked throughout Australia, forcing the Bureau of Meteorology to add new colours (deep purple and pink) to its weather forecasting chart to record temperatures above 50°C.

Australia’s first six days of 2013 were among the hottest 20 days on record in terms of average maximums. The heatwave developed over a large region stretching from northern Victoria and inland New South Wales to central-west Queensland, across to north-western Western Australia and down to the Nullarbor coast.
The national average maximum across Australia on 7 January was 40.33 °C, beating the previous record set in 1972 by 0.16°C.

In Perth, temperatures exceeded 37°C for seven consecutive days. This heatwave caused 20 people to be hospitalised between 27 December and 3 January. St John Ambulance reported a doubling in call-outs for heatstroke, dehydration and burns from the previous week. On New Year’s Eve, Western Australia recorded 42.1 °C, 13 °C above the December average. The state's average temperature for the last week of 2012 averaged a maximum of 39.3 °C, making it the hottest week in 80 years.
 
Records were broken in Alice Springs, with temperatures above 40 °C for 17 days in a row and Oodnadatta, where temperatures exceeded 45 °C for seven consecutive days.

On 17, January Sydney experienced its hottest day ever, with a record temperature of 45.8 °C. The Ambulance Service of New South Wales reported that more than 220 people had been treated for heat exposure or fainting. The heatwave stranded thousands of commuters, with dozens of trains delayed as steel wires buckled and a hose used to run a key signalling system melted. On the central coast, the heat caused an overhead wire to buckle onto a train at approximately 1.30 pm, trapping about 250 passengers for half an hour.

There was a noted increase in nationwide hospital admissions for kidney disease, acute renal failure and heart attacks across this period. The Bureau of Meteorology stated the heatwave was an exceptional event.