Cooler conditions have helped firefighters battling bushfires across Australia, but many are still raging out of control, destroying homes and killing thousands of livestock.

In the Victorian town of Ballarat several homes were destroyed when a fast moving grass fire made its way through the town, located 115km northwest of Melbourne.

Around 400km west of Sydney in the town of Bogan Gate firemen are busy fighting several blazes that hit the rural area in New South Wales.

Even though the temperatures are cooling in the southeast of the country and fires may ease, the Australian Bureau of Meteorology is forecasting 54C next Monday.

Australia is particularly vulnerable to bushfires, fuelled each summer by extreme heat and by what scientists say is creeping climate shift blamed for hotter average temperatures globally.

Authorities warned that much of the country faced extreme fire conditions this season, after several years of cooler conditions that had aided forest growth, but also created tinder dry fire fuel conditions.

In Tasmania, one family had a lucky escape, when quick-thinking grandparents took the five children they were taking care of into the sea.

They huddled under a jetty, as their home burned to the ground.