A total fire ban is in place again across much of New South Wales as hot and windy conditions return.
Temperatures are expected to reach the high 30s and low 40s in many areas on Friday.
AAP reports 80 fires were burning across the state on Thursday night, 15 of them uncontained.
In northern NSW, the Coonabarabran fire broke containment lines at Gowan, cutting the Newell Highway on Friday morning
The 45,000-hectare blaze in the Warrumbungle National Park west of Coonabarabran, has already destroyed 51 properties.
RFS Commissioner Shane Fitzsimmons said the blaze was threatening some rural homes at the southern end of the Coonabarabran fire front.
"We've seen a run of fire to the south and that has resulted in the Newell Highway again being closed," he said.
Other notable fires are those at Deans Gap in the Shoalhaven and Yarrabin in the Cooma-Monaro area, which have been burning continuously since last week.
A grass fire broke out in Penrith in western Sydney on Thursday evening, with firefighters expected to work through the night.
The fire burnt 10,000 hectares at Coombes Drive and Hickeys Lane before it was brought under control.
Victoria
East of Melbourne, a large fire is still out of control in difficult terrain. It has already burnt 8500 hectares of forest and is continuing to expand.
The bushfire started in Aberfeldy on Thursday and is moving at about 1km per hour towards several towns in south-eastern Victoria.
Residents in Glenmaggie have been warned it is now too late to leave their town. The ABC reports an emergency relief centre has been opened at the Baptist church in Sale.
CFA state duty Officer Gary Weir says water bombers will take to the air and strike teams are being brought in from around the state.
"It is very serious at the moment,'' he said.
