SYDNEY (AFP) - Firefighters were battling scores of wildfires raging in Australia on Saturday, as a government commission warned that climate change had raised the risk of scorching heatwaves becoming more frequent.

In the eastern state of New South Wales, some 1,000 firefighters were attempting to douse 95 wildfires, 12 of them burning uncontained, while fires were also burning in neighbouring Victoria and Queensland states.

And in the southern island state of Tasmania, known for its cooler temperatures, residents were returning to the burnt-out homes they fled a week ago when flames raced through villages on the Tasman peninsula.

No deaths have been reported from the bushfires, which have flared during extreme summer temperatures, but the unprecedented heatwave has prompted the government's Climate Commission to issue a new report on the weather event.

It says that climate change has contributed to making the extreme heat conditions - in which record-breaking temperatures in parts of the country have topped 45 deg Cel - and bushfires worse.

"The length, extent and severity of the current heatwave are unprecedented in the measurement record," says the report titled "Off the Charts: Extreme Australian summer heat".

"Although Australia has always had heatwaves, hot days and bushfires, climate change is increasing the risk of more frequent and longer heatwaves and more extreme hot days, as well as exacerbating bushfire conditions."

It says while many factors influence the potential for bushfires, so called "fire weather" is highly sensitive to changes in climatic conditions.

And hotter temperatures, longer heatwaves, high winds and drier soil and grass can all dramatically exacerbate fire conditions.

"Thus when fire occurs in more extreme weather conditions, there is the potential for the fire to be far more intense and difficult to control," the report says.

One of the report's authors, Mr David Karoly, said there was clear evidence of an increasing trend in hot extremes in Australia, where the current heatwave has affected more than 70 per cent of the vast continent nation.

"What it means for the Australian summer is an increased frequency of hot extremes, more hot days, more heat waves and more extreme bush fire days and that's exactly what we've been seeing typically over the last decade and we will see even more frequently in the future," he told the ABC.

Wildfires are a fact of life in arid Australia, where 173 people died in the 2009 Black Saturday firestorm, the nation's worst natural disaster of modern times.

As owners returned to their gutted homes this week in the small communities of Dunalley and Murdunna in Tasmania, they were aware things could have been worse.

"Never mind these things can be replaced, it's not a problem," one man told the ABC as he surveyed his destroyed holiday home in Murdunna.