Hot, dry and windy conditions are fanning fires in multiple states and territories, but the worst could be yet to come for Victoria.
As many Australians enjoy the official start of the holiday period, firefighters are working to contain blazes in almost every jurisdiction.
A smoke warning has been issued due to a grassfire in Smithfield to Adelaide's north, as temperatures in the South Australian capital push towards 36 degrees Celsius.
Total fire bans are in place for the Mount Lofty Ranges and west coast region.
Multiple fires are burning east of Perth and in northwest and southwest WA, and emergency services have warned people to avoid the Laverton area and watch conditions in Bornholm in Albany.
Fire services are working to control minor blazes and scrub fires in the NT, NSW and in Sprent, southwest of Tasmania's Davenport.
In western Victoria's Grampians National Park, where a more-than 40-hectare blaze has burned for days, watch-and-act warnings are still in place and it remains unsafe for people to return to Bellfield, Halls Gap and surrounding areas.
Firefighters from multiple states are assisting their Victorian counterparts as they work to secure containment lines ahead of Boxing Day, which is expected to bring the worst conditions since the 2019 Black Summer.
"There are two major concerns on Thursday – the fires already burning in the landscape, and any new fires that start as a result of the extreme fire risk," Country Fire Authority Chief Officer Jason Heffernan said.
A total fire ban has been declared across the state, with the Bureau of Meteorology forecasting temperatures into the 40s and strong winds of up to 80km/h, with gusts of up to 100km/h in elevated areas.
"That's enough to bring down trees and power lines, cause some minor power outages, but also create dangerous conditions for our ongoing fires through the Grampians," senior meteorologist Dean Narramore said on Wednesday.
Severe Weather Update: Damaging Winds and Extreme Fire Dangers for parts of SA & Vic.— Bureau of Meteorology, Australia (@BOM_au) Video current: 12:00pm AEDT 25 December 2024.For the latest forecasts and warnings, go to our website https://t.co/4W35o8iFmh or the BOM Weather app. pic.twitter.com/jTlZCatMyKDecember 25, 2024
With some residents evacuating from around the park's north today, those remaining defend property have been urged to monitor changing conditions and stay up-to-date with alerts.
The State Control Centre's Luke Hegarty has urged Victorians to observe the total fire ban and ensure all fires are out by midnight.
"If you've been camping, if you've been out in the bush, or if you've been working at home ... Check any fires, make sure they're fully extinguished and help keep Victoria safe," Mr Hegarty said.
A state wide Total Fire Ban has been declared for Victoria on the 26th of Decemeber 2024. I urge all Victorians in fire risk areas to discuss their bushfire survival plan with their household and remember leaving early is the safest option. ℹ️Visit — CFA Chief Officer Jason Heffernan (@CFAChiefOfficer) https://t.co/tQ9PwDGZ4N pic.twitter.com/hKXhMApJgRDecember 24, 2024
Heat-related health risks could also occur, including heat cramps, heat exhaustion and heat stroke, Ambulance Victoria Emergency Management Director Dale Armstrong warned.
Heat stroke is fatal in up to 80 per cent of cases.
"Most at risk are elderly people, young children and those with medical conditions, however heat and heat-related illnesses can affect anybody," Mr Armstrong said.
Victorians have been urged to prepare for outages with provider AusNet warning power faults could be triggered to prevent bushfires starting on Thursday.
As a cool change washes over Victoria on Friday, the extreme fire dangers will push into parts of central northeastern NSW on December 27 and 28.