Victorians are being warned to brace for another heatwave, with temperatures set to soar towards record levels in some parts of the state, putting authorities on alert in fire-affected areas.

South Australia and parts of New South Wales have also been told to prepare for hot weather, due to what the Bureau of Meteorology senior meteorologist Kevin Parkyn described as a “dome of heat” that has caused record-breaking heat in Western Australia moving east.

Saturday will mark the start of the prolonged run of heat – with at least five days above 40C – for inland areas of South Australia, Victoria and NSW, according to the bureau.

On Saturday, Adelaide was expected to reach 42C, while Port Augusta, 300km north of the city, was forecast to hit 46C.

Melbourne was forecast to reach 40C, before dipping to 25C on Sunday and 30C on Monday – thanks to a south-westerly wind change – before rising to 41C on Tuesday. It would be even hotter in state’s north, with Ouyen, near Mildura, forecast to reach 48C.

“Many centres are probably going to approach their all-time maximum records. This is quite a significant day on Tuesday,” Parkyn said.

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While a cool change could then pass through Melbourne on Wednesday, in northern Victoria the hot weather was forecast to continue.

“This could easily be four, five, six, seven days of 40-plus-degree temperatures inland, particularly hanging in there along the Murray,” Parkyn said.

He said there was no with no meaningful rain forecast for the next fortnight. Extreme fire danger was predicted for the south-west and the Wimmera on Saturday.

There were seven major active fires across the Victoria, which may burn for days or weeks. Fires at Walwa, Wonnangatta Complex (Dargo) and Mallacoota were not yet under control.

While the Longwood fire in central Victoria was now contained, it had already destroyed 320 homes and burnt through 144,000 hectares since it started on 9 January.

The Country Fire Authority’s chief officer, Jason Heffernan, stressed that even without the high winds seen two weeks ago, the “the sheer heat and the topography of the landscape” meant those fires now burning could “spread rather rapidly”, resulting in “quite volatile fire behaviour”.

Catastrophic fire danger was also forecast for South Australia’s Yorke peninsula, with extreme fire danger also expected across much of the southern part of the state and the Mount Lofty Ranges.

On Sunday, the extreme fire danger was expected to extend to southern NSW and the ACT.

Records broken in the west

The heat had already ramped up across north-west Western Australia, with widespread temperatures in the high 40s on Tuesday stretching from Kalbarri to Carnarvon, and records broken.

Popular holiday spot Shark Bay reached 49.2C, a January record for the site, while maximums inland at Gascoyne Junction hit 48.9C, the second highest January temperature for that station.

A new record was also set at Carnarvon airport, a site with observations dating back to 1883, with the temperature hitting 47.9C on Tuesday.

On Thursday, temperatures above 45C were expected in parts of WA, with extreme fire danger stretching from north of Perth towards the wheat belt and then down towards places like Albany and Esperance.

A tropical cyclone watch has been issued for tropical low 16U, now 790km north-west of Broome, which had a high risk of becoming Tropical Cyclone Luana as it approached the Kimberley coast on Saturday.

Further ahead, a peak in temperatures on Tuesday could see records topple in Victoria. Mildura airport was forecast to reach 47C, which would be a record (the hottest temperature in January was 46.9C).

Australia experienced its fourth-warmest year on record in 2025, with average temperatures up 1.23C nationally, according to the Bureau of Meteorology.

The climate crisis has increased the frequency and severity of extreme weather events, including heatwaves and bushfires.

Hotter than average days and nights were expected to continue until April for much of the country, according to the latest long-range forecast. Sea surface temperatures would remain warmer than average globally, including around Australia.