More than 350 koalas are estimated to have died in a bushfire on the NSW mid-north coast, with wildlife rescuers declaring the losses a "national tragedy".
The blaze has reportedly scorched two thirds of Crestwood, an area south of Port Macquarie known as a koala breeding ground.
Port Macquarie Koala Hospital president Sue Ashton said at least 350 koalas would be lost, based on a predicted 60 per cent mortality rate.
Ms Ashton said a team of workers would conduct a search and rescue operation once given the all-clear from the NSW Rural Fire Service.
"It will be days of work in really extreme conditions - you're on a fire ground in PPE (personal protective equipment) gear with the weather really starting to heat up," she told AAP on Thursday.
The hospital released graphic footage of koalas lying burned to death on the smouldering ground in Port Macquarie on Wednesday and Ms Ashton said the disaster would take a toll on her volunteers.
"It's a national tragedy," she said.
"It's very confronting. We're actually arranging counselling for our rescuers, because you can imagine finding those sorts of remains is quite traumatic, particularly when you work so hard to keep them alive."
The 2650 hectare blaze was brought under control by authorities on Thursday.
Sydneysiders, meanwhile, woke to another smoky day as haze from the mid-north coast fires causes poor air quality as far south as Bowral.
The Department of Environment declared air quality in Sydney as "poor" due to particles, and those with a chronic respiratory or heart condition have been encouraged to avoid outdoor activity and stay indoors.
The department's air quality index showed parts of the lower Hunter, upper Hunter, Central Coast, Sydney and Illawarra are rated as "hazardous".
The poor air quality is forecast to continue into Friday.
The Bureau of Meteorology says the smoky conditions are likely to continue until late Sunday or early Monday as winds from the north and north east push smoke south.
"Smoke should clear at some stage over the weekend - it's just a little far out at this stage to predict," the NSW RFS said in a statement at 5pm on Thursday.
The RFS said there were 70 fires burning across the state with 44 uncontained, requiring the attention of 1000 firefighters and support staff.
However, rain is expected across the state on Sunday, offering partial relief.
A total fire ban is in place for Friday the greater Hunter, greater Sydney, Illawarra/Shoalhaven, far South Coast, Southern Ranges and Central Ranges areas all facing very high fire danger warnings.
Australian Associated Press