Fire threat not over despite cool change

Fire services in New South Wales are warning of more blazes to come, despite a cool change that's forecast to hit Sydney at four o'clock this morning.

Firefighters have battled more than 140 fires overnight, and a property has been gutted by fire in Jugiong, near the ACT border.

The Rural Fire Service says a total fire ban remains in place today, with residents urged to stay vigilant as crews monitor a southerly change that's not expected to reach Sydney until four o'clock this morning.

Almost one thousand firefighters and 90 aircraft will fight blazes and monitor sites throughout the day, as fire danger ratings are reduced from catastrophic, to severe, very high, or high.

Overnight, police doorknocked homes in the Kybeyan Valley in southern NSW, with the fire expected to move toward Dangelong, Numeralla, and Countegany.

At Deans Gap, a 1500 hectare blaze jumped the Princess Highway overnight; it was burning out of control but the RFS says the fire's intensity has decreased as a result of a southerly change.

Photo: AAP