About 5 million hectares (12.35 million acres) of land have burned nationwide over the past few months, with nine people killed and more than 950 homes destroyed. New South Wales, the country's most populous state, has received the brunt of the damage, with around 850 homes razed in the state.
Parts of New South Wales, including Sydney, experienced cool and damp conditions on Christmas Day, but more than 70 fires continued to burn across the state. New South Wales has been in a seven-day state of emergency, which was to expire on Wednesday night.
About 2,000 firefighters and 400 firetrucks battled the blazes in more favorable conditions, but high temperatures are set to return. Sydney is forecast to hit 31 degrees Celsius (88 Fahrenheit) on Sunday, while the city's western suburbs could reach 41 C (106 F).
Fire danger ratings remained very high in northwestern New South Wales, and were between high and moderate for the rest of the state.
In his annual Christmas message, Prime Minister Scott Morrison paid tribute to the families of the two firefighters _ Geoffrey Keaton, 32, and Andrew O'Dwyer, 36 _ who died last week battling blazes southwest of Sydney.
The wildfire crisis forced Morrison to cut short his much-criticized family vacation in Hawaii. He returned to Australia on Saturday night.
``To Andrew and Geoffrey's parents, we know this is going to be a tough Christmas for you, first one without both those two amazing men,'' he said.
``I want to thank all those who serve our nation, serving as volunteers fighting those fires as we speak,'' Morrison added.
Meanwhile, about 200 firefighters continued to battle a wildfire Wednesday in the Adelaide Hills, which is currently at the ``watch and act'' level issued by the South Australian Country Fire Service.
South Australia state, which last week had 86 homes destroyed after wildfires flared in catastrophic conditions, is bracing for a return of extreme temperatures, with Adelaide, the state capital, expected to reach 41 C (106 F) on Saturday.