Heavy rain fell across parts of fire-ravaged eastern Australia on Thursday and more wet weather was forecast, giving some relief following months of catastrophic blazes fuelled by climate change.

Bushfire smoke disrupted the Australian Open build-up Wednesday for a second straight day to deepen concerns about the fate of the year's first tennis Grand Slam, but a cool change late in the day raised hopes of rain soaking the blazes.

The toxic haze that descended on Melbourne, where the Australian Open is due to begin next week, drifted down from out-of-control fires that have endured for months in eastern and southern Australia.

Exhausted firefighters said they had finally brought Australia's largest "megablaze" under control Monday, as wet weather promised to deliver much-needed respite for countryside ravaged by bushfires.

Bushfires flared in southern Australia on Thursday as a heatwave expected to bring renewed misery set in, and officials warned some areas are "just at the beginning" of the devastating crisis.

Firefighters raced to quell massive bushfires in southeastern Australia Tuesday, taking advantage of a brief drop in temperatures and some much-needed rainfall before another heatwave strikes later this week.

Australia's military launched the seaborne evacuation of hundreds of people trapped in a southeastern town Friday, as the country braced for yet more catastrophic bushfire conditions.

A navy landing craft from HMAS Choules docked in the town of Mallacoota, where residents who had been stuck on the foreshore since New Year's Eve clambered aboard with family, pets and a few belongings. 

Australia ordered residents and tourists out of the path of raging bushfires Thursday as the country braced for a weekend heatwave expected to fan the deadly inferno.

Catastrophic blazes ripped through the country's south-east on New Year's Eve, killing at least eight people and stranding holidaymakers.

Thousands of holidaymakers and locals were forced to flee to beaches in fire-ravaged southeast Australia Tuesday, as blazes ripped through popular tourist areas leaving no escape by land.

A scorching heatwave intensified bushfires ravaging parts of Australia on Saturday, and out-of-control blazes surrounding Sydney worsened under "catastrophic" conditions.

Australia set a record for its hottest day ever for a second straight day, with an average national temperature of 41.9 degrees Celsius (107.4 Fahrenheit), a full degree higher than the previous mark, officials said Thursday.