► Mid North Coast fires continue to burn

A small town in central western NSW has been "all but wiped out" in a bushfire that ravaged the area, a resident claims, as firefighters continue to battle more that 80 blazes burning across the state.

The immediate threat to property from bushfires was downgraded early on Monday morning following cooler and calmer conditions overnight, but firefighters have warned the danger period is not yet over.

Dozens of properties are believed to have been damaged or destroyed, but the NSW Rural Fire Service said it could not provide a precise figure until Building Impact Assessment Teams inspected fire-ravaged areas on Monday to determine the extent of the loss.

A resident of the small town of Uarbry, east of Dunedoo, told the ABC that the town had been "all but wiped out" in a bushfire on Sunday. That bushfire, which the RFS has called the Sir Ivan Fire, had burned about 41,650 hectares by Monday morning and was not yet contained.

Uarbry consists of only about 12 buildings, most of which were no longer standing, residents claimed.

As firefighters across the state battled the extreme conditions, three people were arrested after allegedly lighting fires in NSW.

The arrests prompted an outburst from Rural Fire Service Commissioner Shane Fitzsimmons, who slammed the alleged offenders - males aged 13, 32 and 40 - for the "heinous crimes".

"How dare they," he said.

"You put the lives of our firefighters at risk. How dare anybody add to the extraordinary conditions we're experiencing."

At least one farmer, Warren Jarvis, reported that his house was "totally gone" when a fire raced over the hill near his property near Cassilis and went "mad".

"My house and all my property is totally gone. Three greyhounds, other cats, all my chooks, probably my sheep and cattle," he said.

Just before 6am on Monday, the two biggest fires - the Sir Ivan Fire, to the east of Dunedoo, and at Kains Flat, south of Kempsey - were both at Watch and Act level. That is one level below an emergency warning, and means there is still a heightened level of threat and conditions are changing.

The RFS said the Sir Ivan Fire was not contained and was moving north towards Leadville and Coolah. It had already burned 41,650 hectares of land by early on Monday morning, the RFS said.

"The fire is currently burning to the east of Dunedoo moving in a northerly direction towards Black Stump Way, Leadville and Coolah," a RFS spokesman said.

"Follow the directions of firefighters in the area. Telecommunications may be disrupted in the area due to power outages."

The Kains Flat fire, north-east of Mudgee, was out of control and moving in an easterly direction just before 6am on Monday.

"If it is your plan to leave, or if you are not prepared to stay, people in the area around Wollar and Cumbo, including Mogo Road and Araluen Lane, should leave now towards Bylong.

"People in the area around Wollar and Cumbo should remain vigilant and prepared to implement their bushfire survival plan."