As temperatures soared above 44 degrees Celsius (111 degrees Fahrenheit), hundreds of firefighters backed by aircraft battled the blazes, while sweltering residents of coastal cities flocked to the beaches.

To the north of Sydney, capital of New South Wales and Australia's most populous city, four fires were burning out of control on the central coast, with flames of up to 20 metres (66 feet) high.

More than 50 homes in Woy Woy Bay, across the Pittwater estuary from Sydney's upmarket Palm Beach, had been evacuated and several properties and cars were burnt, national radio reported.

Helicopters dropped water bombs to help firefighters struggling to bring the blazes under control as they threatened to engulf more homes in nearby towns.

Major roads from Sydney to the central coast were closed.

In Sydney itself, where the temperature reached 44.7 degrees (112 degrees Fahrenheit) at the international airport, a total fire ban was imposed and walking tracks in nearby national parks were closed.

New South Wales fire officials said some 3,000 firefighters were on high alert, with weather conditions expected to worsen across the state later in the day.

"Unfortunately the winds look like they are picking up at this stage and we are expecting them to increase over the rest of the afternoon," said spokeswoman Rebel Talbert.

The fire service has asked farmers in the state's south to stop harvesting because of fears that sparks from machinery could start a fire.

In neighbouring Victoria state a major fire destroyed five homes as it swept across a 30 kilometre (18 mile) front, officials said.

The fire has burned through about 9,000 hectares (22,000 acres) of bush and farmland, damaging dozens of properties and leaving two people injured.

The government's bureau of meteorology said recently that average temperatures for the first 10 months of 2005 were 1.03 degrees above the 30-year mean and that the country was on track for the hottest year on record.

The city of Melbourne, capital of Victoria state, topped off its warmest-ever December with a record hot New Year's Eve, the bureau said.

The temperature peaked at a scorching 42.9 degrees, breaking the previous record of 41.7 degrees on December 31, 1862.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.