Thousands of voluntary firemen were drafted in to help regular emergency services staff combat the flames, which charred an area of bush almost three times the size of Greater London, or more than 500,000 hectares (1.24 million acres).

"After one of the most protracted bushfire fighting campaigns in our state's history, it is clear that the weather has finally turned in our favour," said New South Wales Rural Fire Service commissioner Phil Koperberg in a statement.

"While the crisis point is now passed, the work goes on for our volunteer firefighters who will continue to monitor over 3,200 km (1,990 miles) of fire perimeter to ensure there are no breakouts or re-ignitions of the fires."

While the storm that moved up the Sydney coast during the night brought relief to the firefighters, it also delivered a cruel blow to one household.

Police said a home in a city suburb near the frontline of the battle against the bushfires, which managed to escape being engulfed in flames, was struck by lightning this week evening and burned to the ground.

The fires - many suspected to have been deliberately lit by arsonists - were the most intense since 1994, when fires around Sydney killed four people and just over 200 homes were lost.

Australia's most deadly modern fires swept through Victoria and South Australia states in 1983, killing 76 people.

Insurance companies say they expect claims to total A$70 million (US$36.4 million) from this Christmas's fires, and officials say another A$70 million was spent fighting the flames.

Fire is part of the natural cycle in the Australian bush, where eucalyptus trees and banksias wait for flames to crack their seedpods, stimulating regeneration.

While the 100 or so blazes around Sydney won all the attention because of their proximity to urban areas, a farmer and his son have been fighting a one-million-acre bushfire all on their own on their remote Northern Territory cattle station.