A total fire ban is once again in place across much of NSW amid fears the return of hot and windy conditions could exacerbate fires already blazing across the state.
With temperatures expected to soar into the high 30s and low 40s in many of the worst-affected areas on Friday, the RFS is bracing for possible further fire outbreaks.
In northern NSW, 150 firefighters were continuing to battle the 45,000-hectare blaze in the Warrumbungle National Park west of Coonabarabran, which has destroyed 51 properties.
Prime Minister Julia Gillard visited the area on Thursday and paid tribute to the bravery and stoicism of residents who were hit by NSW's most destructive fire in more than a decade.
On Thursday night, there were 80 fires burning across the state, 15 of them uncontained.
A bushfire in the Bugaldie area near Coonabarabran was causing concern, with the fire blazing close to some rural properties.
Other notable fires are those at Deans Gap in the Shoalhaven and Yarrabin in the Cooma-Monaro area, which have been burning continuously since threatening properties last week.
"With the warm weather coming through tomorrow, there is that chance that they could reignite and break containment lines," an RFS spokesman told AAP.
A total fire ban is in place for the Sydney region and most of of the rest of the state on Friday.
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.
Although close to industrial buildings, it was not posing any threat to them or residential properties, an RFS spokeswoman said.