More than 1,500 firefighters were battling 55 fires across New South Wales state as temperatures rose to almost 104 degrees.
The worst blazes raged in the western Sydney suburb of Londonderry and on the outskirts of Newcastle, an industrial city about 90 miles north, Fire Service spokeswoman Meeka Bailey said.
In Londonderry, special aircraft helped 35 fire crews battle two fires that were closing in on at least four homes.
In Newcastle, a wood products factory and a tire store were both ablaze Tuesday night, and several explosions rocked the buildings.
More than 200 residents were evacuated to centers set up by the state Department of Community Services as the fires damaged one home and threatened at least 40 others in the area. Firefighters also evacuated passengers from a stranded train.
Summer wildfires are a regular occurrence in Australia, where high temperatures and hot, dry winds from the central deserts can fan flames that spread across hundreds of thousands of miles, mostly in the populous eastern states.
More than 100 fires destroyed 170 homes and dozens of commercial properties in and around Sydney last year from Christmas to New Year's Day, but caused no deaths or major injuries.
