More than 150 blazes are still burning across NSW as a hot and windy weekend forecast prompts a fresh warning for residents to prepare for fire.
A "watch and act" alert was issued on Thursday evening for a bushfire in the Tallaganda National Park, west of Braidwood, in the state's southeast.
The blaze has burnt more than 1150 hectares.
"With more than 150 fires burning across NSW and the forecast of more hot and windy weather for the weekend please use this time to prepare," the NSW Rural Fire Service tweeted on Thursday morning.
"Review your bushfire plan, prepare your properties and discuss as a household what you will do if threatened by fire."
The Bureau of Meteorology said lightning strikes from thunderstorms which hit Sydney and the state's northeast on Tuesday had sparked fresh blazes, with an estimated 100 new fires igniting in a 24-hour period.
On Thursday evening, 61 of the 154 bush and grass fires across NSW were uncontained.
More than 2000 firefighters and support personnel continue to work to slow the progress of the fires, the RFS tweeted.
While there are no total fire bans in place for Thursday, the Greater Hunter, Greater Sydney, Illawarra-Shoalhaven, Southern Ranges, Central Ranges and Northern Slopes are under "very high" fire danger rating, as is the ACT.
Total fire bans are in place for Friday for the Monaro Alpine, Southern Ranges, Central Ranges, North Western and Southern Slopes fire regions.
These regions, along with the Greater Hunter, Greater Sydney, Illawarra/Shoalhaven, far South Coast, Northern Slopes and Eastern Riverina regions will be under "very high" fire danger, along with the ACT.
Sydney's air quality is forecast to be "poor" once again on Friday due to particles.
The Department of Planning, Industry and Environment issued a warning: "Unhealthy for sensitive people, and could cause symptoms, especially in people with heart or lung disease."
Armidale and Tamworth both recorded "hazardous" air quality levels for particles on Thursday evening, while Muswellbrook and Singleton in the upper Hunter region were classified as "very poor".
Meanwhile actor Russell Crowe, whose Nana Glen property near Coffs Harbour was hit by bushfires a few weeks ago, has pledged to triple the highest bid on a hat he is auctioning off to raise funds for the RFS.
Crowe, who on Tuesday released video footage of a NSW forest scorched by bushfires, said on Thursday he had received a bid of more than $US2000 for the "slightly worn" baseball cap.
Alongside a picture of the white hat with the South Sydney Rabbitohs logo, he tweeted: "Should I auction this hat off? Signed and personalised to the highest bidder? I'll double or triple the winning bid and donate the $ to the [?]@NSWRFS."
On Thursday the highest bid was at $US3100.
Crowe said the auction would close on Friday morning.
He was not in the country at the time of the bushfires and said his family was safe.
Australian Associated Press