After "a hell of a week", NSW's bushfire crisis is not over yet, the state's acting premier says.
A fire in Warrumbungle National Park, west of Coonabarabran in the central west, destroyed at least 33 homes and damaged the Siding Spring Observatory yesterday.
Fifty farm sheds were also lost along with many livestock, much fencing and farm machinery.
It is one of 146 blazes statewide that are testing almost 800 firefighters.
The Warrumbungle fire burnt through 40,000 hectares after starting its destructive run on Sunday.
Yesterday it still had a 100-kilometre front, although no more properties were under urgent threat.
Rural Fire Service (RFS) Deputy Commissioner Rob Rogers said a wind shift at the worst possible time had created "perfect storm" conditions for a fire that burnt with a ferocity not seen in years.
"There was just absolutely no stopping that fire," he said.
Acting Premier Andrew Stoner said while a subsequent wind change had removed the threat to the town of Coonabarabran it could threaten settlements north of the national park.
More than 110 people were evacuated to the Tattersalls Hotel in Baradine and a relocation centre was established at the Coonabarabran Bowling Club, with residents warned it was not safe to go home.
Mr Stoner said it was "miraculous" the main building and Australia's largest telescope at the Siding Spring Observatory were not destroyed, although the fire damaged the Australian National University (ANU) facility.
ANU acting vice-chancellor Erik Lithander said the observatory would be closed for two weeks while a full assessment was done.
Dr Lithander said 18 staff were evacuated from the site on Sunday afternoon and though they were safe, there were fears some had lost their nearby homes in the blaze.
At least five buildings at the observatory had been damaged significantly, including the lodge used to accommodate visitors, the visitors' centre, a number of residential cottages used by staff and several sheds.
"We do not yet know what impact the extreme heat or the ash might have on the telescopes themselves and we won't be able to carry out that assessment until we can enter the buildings and inspect the inside of them," Dr Lithander said.
While easing conditions had helped stop the fire spreading, yesterday more than 770 firefighters, 208 trucks and 78 aircraft were deployed to tackle the 146 fires, 36 of which are not contained and 13 which are out of control. AAP
Main developments yesterday:
33 homes and more than 50 sheds lost in the Wambelong fire near Coonabarabran. Figures expected to rise.
One building destroyed at Siding Spring Observatory.
• Warrumbungle National Park, west of Coonabarabran. Fire out of control. Almost 40,000hectares burnt. Watch and alert warning applies.
• Near Redbank Trail 35kilometres north-east of Coonabarabran along Newell Highway. Fire out of control. Two hectares burnt. Watch and alert warning applies.
• Yarrabin, 20kilometres east of Cooma in the Kybeyan area. Fire has burnt through more than 1200hectares but being controlled and warning downgraded.
• Bundabarina, 10kilometres west of Collarenebri on Walgett Road near Walgett. Has burnt 750hectares. Warning downgraded.
At a glance:
• 146 fires, 13 out of control and 36 uncontained.
• 500,000 hectares burnt so far.