A recent respite for Australian firefighters that brought rains and cooler weather is set to end, meteorologists warned on Monday, with hot conditions forecast for later this week raising a risk that blazes may start spreading again.

Australia experiences regular bush fires in the summer, but this season's fires began early and have claimed 33 lives in the past four months, killed millions of animals and charred an area nearly the size of Greece.

More than a week of solid rain in Victoria, New South Wales, and Queensland, the three states most affected by the fires, has more than halved the number of blazes, but above average temperatures were set to return by the weekend.