Millions of NSW residents are breathing a sigh of relief after a day of catastrophic fire danger passed without loss of life, but authorities are warning that strengthening winds mean properties are still at risk.
The Rural Fire Service has confirmed at least 50 homes were damaged or destroyed on Tuesday, but there were no fatalities on a day of "catastrophic" conditions in the Sydney, Hunter and Illawarra-Shoalhaven regions.
"We are starting to see conditions actually deteriorate, especially in the mid-north coast area," RFS spokesman Inspector Ben Shepherd told ABC TV on Wednesday afternoon.
"As the winds warm up, there is a likelihood the fires will move once again and threaten properties. We've still got a long day ahead."
RFS Commissioner Shane Fitzsimmons admitted firefighters were "deflated" by the property losses.
Residents on the NSW mid-north coast were urged to seek shelter after an emergency fire danger rating was issued on Wednesday for the Hillville bushfire burning across more than 22,000 hectares.
The blaze was downgraded to watch and act late on Wednesday afternoon.
At one point on Tuesday, 16 fires were simultaneously at "emergency" level - just shy of the record of 17 set on Friday.
Since then more than 300 homes have been severely damaged or destroyed. Three people have died.
Premier Gladys Berejiklian said she was hugely relieved thousands of amazing volunteers and emergency service personnel withstood the catastrophic conditions and saved lives and property.
NSW remains in a week-long state of emergency with some 3000 firefighters on hand to battle the 60 or so blazes still burning. Twenty-two of them are uncontained with more than a dozen at "watch and act" alert level.
A statewide total fire ban remains in place on Wednesday.
Police said they are working to establish the cause of several fires which broke out on Tuesday, to determine whether any were started deliberately.
Fire danger is "very high" for the Greater Sydney, Greater Hunter, Illawarra-Shoalhaven, southern ranges, central ranges, northwestern, northern slopes, north coast and far north coast regions.
New England is one level higher at "severe".
The Insurance Council of Australia on Wednesday afternoon said insurers had received 450 claim applications from catastrophe-hit areas, with initial losses at 80 properties totalling $50 million.
Severe conditions are forecast again this weekend.
Mr Fitzsimmons said that would be followed by another burst of hot air next week meaning crews "simply aren't going to get the upper hand on all of these fires".
Defence forces are standing by to provide support, including search and rescue operations and other logistical duties.
© AAP 2019