Residents in parts of southern and eastern Australia are expected to swelter over the next few days, with temperatures forecast to rise to the low 40s.
The Bureau of Meteorology is warning low intensity heatwave conditions will develop across parts of South Australia, Victoria, Tasmania and the Northern Territory on Friday.
Pockets of severe intensity heatwaves will also develop across southeast Victoria, northeast Tasmania and southeast NSW.
The heatwave will become widespread across those states and into southern Queensland on Friday afternoon.
Dry thunderstorms are also possible, leading to the risk of fires.
Extreme fire danger warnings are already in place across parts of South Australia, while Victoria's Country Fire Authority declared a total fire ban day for Melbourne on Friday.
A number of fires are still ongoing in eastern Australia, in particular across Queensland's Western Downs region.
Victoria, Tasmania and southwestern NSW will experience some relief from the heat over the weekend, with temperatures forecast to drop.
But residents in Western Australia will continue to swelter with temperatures in some remote areas expected to exceed 45 degrees Celsius.
Isolated thunderstorms with little rainfall and damaging winds are possible over northern and inland parts of WA.
Meanwhile, parts of northern Queensland are on monsoon watch, with minor to moderate flooding likely.
