Why is there a heatwave in Australia?
As of December 5, 2025, a major heatwave is affecting Western Australia, central Australia, and New South Wales, with the most extreme temperatures recorded inland.
The heatwave is caused by a large mass of hot inland air moving east across the country. Persistent northwesterly winds are pushing dry, hot air from central Australia toward the coast, raising temperatures more than 10°C above average in many places (1).
Along coastal New South Wales, including Sydney, temperatures are especially intense because warm night-time temperatures prevent the body from cooling down. This increases health risks, especially for vulnerable groups.
How long will the heatwave last?
The heatwave began on December 1, 2025, when hot air formed over Western Australia and moved east.
In Sydney and coastal New South Wales, the peak of the heatwave will occur from Friday December 5 through Saturday December 6. Western Sydney could reach around 40–41°C on both days (2).
A strong cool change is expected late Saturday into early Sunday, quickly dropping temperatures by up to 15°C and ending the heatwave for most coastal areas by December 7.
Inland northern regions, including the Kimberley, Pilbara and northwest Queensland are expected to remain above 40°C well into next week (3).
Are there any alerts in place?
A severe heatwave warning is active for the New South Wales coastline, including the Hunter, Sydney, Illawarra and South Coast. Residents are advised to stay hydrated, avoid prolonged heat exposure and monitor vulnerable people (4).
A severe heatwave warning is also in place for Gulf Country in Queensland. Western Australia remains under a heatwave warning for the Kimberley, Pilbara and North Interior.
Fire danger is extreme across several regions in New South Wales, and total fire bans are in place for the Riverina and Central West. Victoria and South Australia also have extreme fire danger ratings and total fire bans in several districts (5).
