Parts of Australia will face catastrophic fire conditions on Friday, when heatwaves are expected to hit most of the country.

Severe to extreme heatwaves have been declared in every state and territory in Australia, except for Queensland, with high temperatures forecast for days.

The state of Victoria has declared a total fire ban for Friday, as the fire danger rating will be set at 'catastrophic' - the highest level. Some 450 schools and childcare centres will be closed.

One meteorologist told the BBC that the combination of heatwaves and an elevated fire danger in parts of the country could create the most 'significant' conditions since the devastating Black Summer bushfires.

On Thursday, firefighters battled several blazes in Victoria and New South Wales (NSW), with a dozen planes carrying water called in to tackle a large fire near the city of Wodonga, the ABC reported.

Melbourne experienced its hottest day in six years on Wednesday with a high of 40.9C (105.6F), while some coastal towns in Western Australia hit 49C.

In NSW, the heatwave is expected to peak on Saturday with Sydney facing a high of 42C while areas of South Australia and Western Australia will see temperatures over 40C in the coming days.

Friday will be the 'real peak of the current burst of heat,' according to Angus Hines from the Bureau of Meteorology.

This heatwave event is projected to be the most significant multi-day situation for inland south-east Australia since 2019-2020, which marked the country's most severe fire season on record.

In light of the catastrophic fire danger, Victoria's Emergency Management Commissioner has urged residents to prepare and follow bushfire survival plans, stressing the unpredictability and potential danger of blazes under these conditions.

Authorities are vigilant, recognizing the critical need for community cooperation in protecting lives and property, especially as existing fire danger ratings categorize the current conditions as catastrophic.