Hundreds of firefighters battled some 30 uncontrolled bushfires across New South Wales on Sunday including a "large and dangerous" fire that threatened a world-leading observatory in Warrumbungle National Park.
Police evacuated residents in the area around Siding Spring in the north of the Australian state on Sunday afternoon after the Rural Fire Service issued an emergency warning.
"This is a large and dangerous bush fire. It is burning in the area around Timor Road near Siding Spring Observatory," the emergency warning said.
Administered by the Australian National University's research school of astronomy and astrophysics, the Siding Spring Observatory is the nation's top optical and infrared observatory and one of the top facilities of its kind in the world.
The fire, west of Coonabarabran, was also threatening about a dozen isolated properties at Mt Woorut.
AAP reports that firefighters and waterbombing aircraft are on scene.
The Mt Woorut fire is one of 30 fires that remain uncontained in New South Wales.
Meanwhile, a cool change has brought relief to NSW Rural Fire Service officers fighting bushfires in other areas across the state.
On Sunday, more than 190 firefighters worked to contain a bushfire burning 12km west of Sussex Inlet, near Shoalhaven.
The fire has burnt more than 8400 hectares but there was no immediate threat to properties.
At Yarrabin, near Cooma, more than 100 firefighters continued to establish containment lines and extinguish spot fires, with no threat to properties.
The fire has burnt through more than 9800 hectares of bushland and was moving away from Cooma in an easterly direction.
Near Yass, more than 70 firefighters worked on containment lines around a fire and the blaze has been contained.
In the state's north about 20 fires continue to burn uncontained after lightning storms on Saturday night ignited 45 new fires.
The ABC reports that in Tasmania the main highway through the state's bushfire-stricken south-east will re-open on Sunday, allowing more residents to return to their devastated communities.
Authorities in the state have been keeping a close eye on a bushfire at Lake Repulse that has burnt more than 11,500 hectares.
In the state's south-east crews will continue back-burning near a bushfire that has destroyed 24,000 hectares and 170 properties on the Tasman Peninsula.
In Victoria, cooler conditions are allowing firefighters to extinguish hotspots from fires that have been contained in the past few days.