Residents in regional Victoria have been warned their lives are in danger as two bushfires in the west of the state intensify and spread in extreme conditions.

Emergency warnings have been issued for a blaze at Little Desert National Park that is believed to have been sparked by dry lightning and is creating its own weather system.

The fire is threatening homes and lives, but locals were advised it was too late to evacuate and they “must take shelter now”.

“If you have not already left, the time to safely evacuate has now passed. Take shelter indoors immediately. It is now too dangerous to leave,” VicEmergency said on Monday.

Alerts were issued early on Tuesday for the town of Dimboola. Earlier, there were alerts for Gerang Gerung, Kiata, Kinimakatka, Lawloit, Little Desert, Miram, Winiam, Winiam East.

Little Desert National Park is alight, possibly caused by dry lightning strikes. Photo: State Control Centre

Victorian State Control Centre spokesman Luke Heagerty said the fire was spreading rapidly and engulfing a vast area. 

“There’s a lot of energy that this fire is creating, and what that means is it’s effectively creating its own weather system,” Heagerty told the ABC.

“Even with the cool change, there will still be a lot of smoke around, a lot of potential for this fire to continue to behave in ways that it otherwise wouldn’t, just because of the intensity of this fire.”

Another fire burning in the Southern Grampians also intensified and residents were ordered to evacuate.

There were extreme fire danger warnings across Victoria and South Australia on Monday as temperatures shot to 40 degrees.

The combination of hot, dry, windy conditions and dry lightning meant fires would be uncontrollable and lead to dangerous and erratic behaviour, Bureau of Meteorology senior meteorologist Dean Narramore said.

“These hot, dry and northerly winds are likely to lead to temperatures 12 to 14 degrees above average for this time of year, and dry lighting also likely to develop on and ahead of the change,” he said.

Fires are burning near Dimboola, western Victoria. Photo: Facebook/Chris O’Connell

Temperatures in northern Victoria and some regions of NSW had soared into the low to mid 40s by late afternoon Monday.

In South Australia, police and CFS responded to a grass fire at Panorama, near Blackwood in the Mount Lofty Ranges, containing the blaze without the loss of any property.

A grass fire at Kanmantoo in the Adelaide Hills was also contained and in the Barossa Valley, CFS crews responded to a grassfire at Rowland Flat.

Southern Tasmania is also under total fire ban with hot and windy conditions.

Amid the hot, dry weather, Adelaide has fired up its desalination plant after 2024 brought the lowest inflows to the city’s reservoirs in 40 years.

It was Adelaide’s driest year since 2006, with only 347 millimetres of rain, nearly 200 millimetres below average.

Combined reservoir levels are at 44 per cent, the lowest level for more than 20 years. But the city’s water supply was secure, with enough to meet the community needs, SA Housing and Urban Development Minister Nick Champion said.

The desalination plant will temporarily produce up to 300 million litres of water a day during February. The city would otherwise face water restrictions.

“If we didn’t have this plant, I would be having sleepless nights,” Champion said.

Severe storms risk

The weekend’s heatwave conditions are spreading into NSW, with the state expected to face risks as the pool of very hot air that sent temperatures soaring in the south arrives on Tuesday.

Most of NSW, including Sydney and some of its western suburbs, could expect temperatures in the high 30s or low 40s on Tuesday, senior meteorologist Angus Hines said.

“It will become what we call a bit of a southerly buster and shoot up that coast with a bit of ferocity, bringing some very strong winds and a very sharp temperature drop — and for Sydney, that’s forecast to be around 4pm,” he said.

“The temperature could plummet about 15 degrees … and the wind will also pick up and become very strong.”

The change could also spark potentially severe thunderstorms, mostly around the eastern ranges and out towards the east coast.

“If that happens, those severe storms could bring damaging wind gusts, large hail or heavy rainfall that could lead to flash flooding,” Hines said.

“It could be a very active day of weather across NSW, starting with the heat and then coming in with the storms and the sharp temperature drop and the powerful winds.”

On the other side of the country, heatwave conditions from last week are repeating, with temperatures forecast to be 4-12 degrees warmer than the typical January averages across western parts of Western Australia — and up into the 40s in the next couple of days.

A tropical north would also be a focus for forecasters in coming days, Hines said, with rainfall intensifying across north-east Queensland.

“There is likely to be a heavy rain warning issued for some parts of the coast, mostly between Cairns and Townsville,” he said.

“When we start looking towards next week, we see the potential for tropical cyclone development for a few areas across northern Australia.”

This includes the Coral Sea off the north-east Queensland coast, in the Gulf of Carpentaria and potentially off the north coast of WA.

“There’s still quite a few days until that’s likely to happen, but certainly, anyone living in the northern latitudes of Australia should be keeping an eye on the forecast and the warnings as we approach the end of this week,” Hines said.

-with AAP