Heatwave not expected to end until Tuesday or Wednesday as fires burn in multiple national parks

South-eastern states sweltering in a heatwave may be waiting until late Tuesday or Wednesday for a cool change to bring some relief.

On Monday, temperatures in Melbourne peaked at 37.8C just before 4pm, after a high of 38C on Sunday.

Victoria’s emergency authorities have warned that the state’s fire season could extend until early March, with dry lighting overnight sparking new fires.

In Adelaide, temperatures reached a high of 41.2C just before 5pm, after a top of 39C on Sunday.

Senior BoM meteorologist Miriam Bradbury said the capital cities’ three-day run of “intensely hot” weather was remarkable, especially because the last time Melbourne had three days in a row over 37C was in 2014.

“[In] all of these areas, we’re pretty used to seeing one hot day, maybe two hot days, but getting a stretch of three or more in a row is fairly unusual,” she said.

Three or more days of unusually hot weather triggered heatwave conditions, and also meant very warm nights in between very hot days, Bradbury said.

“That does have an impact on the body, where we can’t recuperate from the heat of the day.”

Jonathan Fischer, a meteorologist at the BoM said it was the first time since 2019 that Adelaide had seen back-to-back days of 40C or more. He said a cool change could be short-lived with more hot weather expected.

Victoria’s state emergency management commissioner, Rick Nugent, on Monday afternoon said there was one fire in the Little Desert national park and two in the Grampians national park.

The Little Desert fire covers 84,000 hectares, while those burning in the Grampians total 46,000 hectares.

Crews battling the Little Desert fire faced a hard slog on Monday, when the fire broke containment lines and moved rapidly into agricultural land.

There were four new fires in the Great Otway national park, Nugent said.

“In terms of the high risk season, it is far from over,” he said.

Firefighters were preparing for an even tougher day on Wednesday as southerly winds make conditions worse.

Two houses and a shed were destroyed as 114 fires broke out, mostly from dry lightning, in the heat and storm that battered the state on Sunday and early Monday.

The properties were caught in a fire that started at Nangiloc, in the far northwest of Victoria.

The Victorian premier, Jacinta Allan, said several days of extreme temperatures had a cumulative effect, particularly on vulnerable people.

“Please check in on your loved ones, please check in on your neighbour and also look after yourself as we go through this period of extreme heat.”

Heatwaves are Australia’s deadliest natural phenomenon, killing more people than bushfires, floods and storms.

The Victorian government’s Better Health Channel outlined the symptoms of heat-related illness, which include cramps, exhaustion and heatstroke, and offered advice about staying cool, including drinking plenty of water, spending time in air-conditioned spaces, wearing light and loose clothing, and taking cool showers or keeping your skin wet.

Dr Kimberly Humphrey, a public health medical consultant with SA Health, said the colour of urine was one way to tell whether someone was drinking enough water. “We want it to be nice and clear, and that means you’re maintaining hydration.”

Hobart reached a high of 34C , which was “really hot compared to how it usually should be in summer”, Bradbury said. She said the average for Hobart in February was 21.8C.

Temperatures at least 10C above average were a “common story across much of the south-eastern part of the country today”, she said.

Widespread thunderstorms in Melbourne, “which seemed to rage for hours” on Sunday night, had not brought cooler weather, Bradbury said.

Melburnians would have to wait until Tuesday evening or Wednesday morning for a cold front to reduce temperatures and hopefully lead to “a much better sleep”, she said.

High fire danger was forecast for fire districts across much of the south-east.

In Western Australia, another surge of heat was building, which was expected to push temperatures well above average across much of the state’s south by Thursday and Friday. That would extend across the rest of southern Australia by next weekend, Bradbury said.

Perth had already seen a number of prolonged periods of heat during the 2024-25 summer, a pattern that was likely to continue, she said.

“It’s this cycle that we’ve seen quite a bit, where, as soon as one burst of heat clears the east coast, we get another burst of heat building in the west coming across.”

Australia’s land surface has warmed by 1.5C since 1910, according to BoM, with the climate crisis making heatwaves longer and more intense, and increasing the number of extremely hot days.

Data from the BoM showed January 2025 was more than 2C above the long term average for the month, and the second-warmest January on record.

With reporting by Adeshola Ore and Australian Associated Press