Conditions ease across Wollemi National Park bushfire

Firecrews have managed to bring a blaze burning north-west of Sydney under control overnight, but not before it burnt through 6,700 hectares of bushland.

The fire is burning in an easterly direction towards Bakers Valley Road and Gibbs Creek Road/Putty Valley Road in Putty, in the Singleton Shire, with strong winds still fanning the flames.

Firefighters have been liaising with residents in the area and remain on scene to protect rural properties.

Smoke and embers may also be experienced in the Howes Valley and Garland Valley areas.

The alert level has been downgraded to advice and authorities are urging resident to continue to use their Bush Fire Survival Plan.

The blaze sparked after a day of searing heat and strong winds across NSW, with the fire danger in the state at its highest level for the season.

Total fire bans are in place again on Thursday for the Greater Hunter, Greater Sydney, Illawarra/Shoalhaven, ACT, Southern Ranges, Central Ranges, New England, Northern Slopes, North West and Southern Slopes.

The heatwave is likely to stick around until Friday.