Scores of fires are still burning in New South Wales amid temperatures of 35C (95F) and winds of 80km/h (50mph).
A feared southerly wind change has now occurred but the "catastrophic" day feared has largely been avoided.
No deaths were reported on Tuesday but fire chiefs warned that conditions meant the dangers facing the state were far from over.
About six million people live in New South Wales (NSW) state.
The number of fires still afflicting NSW ranged from 100 to 300 in Australian media reports.
Crews have been battling a front spanning 1,000km (620 miles) along the north coast of NSW, with several blazes "exceeding 100,000 hectares alone", officials have said.
Flame retardant had to be dropped in Sydney's northern suburbs as some bushfires approached within 15km (nine miles) of the city centre.