The New South Wales Rural Fire Service said the bushfire burning in the Wollemi National Park area had reached 309,000 hectares in size (about 1,200 square miles) by December 9.
The Gospers Mountain fire was being controlled, the fire service said, but conditions were expected to deteriorate on Tuesday as temperatures were predicted to soar past 40 C (104 F) in greater Sydney, the Hunter, the Illawarra, and northern parts of New South Wales, reports said.
The fire was in danger of spreading to the east and north.
This footage was shared by Gena Dray, who said she filmed it at 10.30 pm on Saturday night. Credit: Gena Dray via Storyful