NSW firefighters are continuing to battle bushfires throughout the state ahead of worsening conditions, with the fire danger in some areas set at the highest level.
A catastrophic fire danger is forecast for the Greater Sydney and Greater Hunter areas on Tuesday after ferocious blazes in northern NSW over the weekend claimed three lives and destroyed at least 150 homes.
Large areas of the state are also predicted to see severe and extreme fire danger.
"We've got big population centres covered by that catastrophic fire danger," RFS spokesman Anthony Clark told the ABC on Sunday.
"But also up on the north coast where we've simply got a lot of fires burning at the moment, those fires have got a real potential to run and impact on lives and properties on Tuesday.
"So the risk is very real."
Mr Clark said that around the Sydney area, they were "really concerned" about the urban fringe.
"Built-up areas where people live such as the northern suburbs of Sydney, up through the Central Coast, the Blue Mountains, the Sutherland Shire - if you're living anywhere near the bush, you are at risk," he said.
A statewide total fire ban has been declared for Monday and Tuesday.
Large parts of the state will be subject to high and very high fire danger on Monday, and more than 40 schools will be closed.
The NSW National Parks and Wildlife Service will also expand closures of national parks and reserves until further notice.
Although authorities are still to complete a detailed assessment of damage caused by the weekend's fires, the RFS said at least 150 homes had been destroyed.
A woman who died as she tried to flee the fires was identified by media on Sunday as Julie Fletcher, 63.
Ms Fletcher's body was discovered on Saturday night in a burnt-out home in the town of Johns River, 40km north of Taree on the mid-north coast.
Wytaliba residents Vivian Chaplain, 69, and George Nole were also named as victims, with people taking to social media to pay tribute to each of them.
Australian Associated Press