Bushfire-affected NSW communities are facing one of the nation's biggest-ever clean-up efforts with authorities fearing dozens more homes may have been lost at the weekend.

Coalition frontbencher Andrew Constance on Monday noted more funds were being made available by the Red Cross with $20,000 per household now accessible for those who have lost everything.

Additional funds will also flow for burn victims and people whose properties were damaged.

"This is not going to be over within weeks, we've got months and years of recovery and rebuilding ahead," Mr Constance said in his home electorate of Bega.

We've got months and years of recovery and rebuilding ahead Andrew Constance

"We are seeing a wave on wave effect following the disastrous bushfires on New Year's Eve and the fires that have beset our region throughout January."

The roads minister urged people to register with Service NSW to access money for clean-up works which will be funded by the federal and state governments.

"It is going to be one of the biggest clean-ups that we've ever seen in our nation's history," he said, adding asbestos would need to be carefully dealt with too.

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Federal Treasurer Josh Frydenberg last week said the average cost to clean up a site was about $50,000 with the cost rising if hazardous materials were involved.

Some 2400 homes, another 260 facilities and 5200 outbuildings have been destroyed in NSW to date this bushfire season.

The so-called Calabash blaze in the Snowy Monaro region was elevated to an emergency warning level on Monday evening.

EMERGENCY WARNING - Calabash (Snowy Monaro LGA)

The fire is spreading E & NE direction under strong SW winds.

People in the Tinderry, Calabash areas including Calabash Rd, Tinderry Rd, Egans Rd and Naylers Lane, should seek shelter as fire approaches. #nswrfs #nswfires pic.twitter.com/3vhugKthBc — NSW RFS (@NSWRFS) February 3, 2020

The bushfire south of Canberra started as a spot fire from the Orroral Valley blaze in the ACT.

"The fire is spreading in an easterly and northeasterly direction under strong southwesterly winds," the NSW Rural Fire Service warned at 5.30pm.

RFS spokesman James Morris says building impact assessment crews are still to determine how many homes were lost in Saturday's fires in the Bega Valley and on the South Coast.

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"We've [still] got very high fire danger for widespread parts of NSW between the Queensland border right down to the Victorian border so it could be another challenging day ahead for firefighters," Mr Morris told ABC radio on Monday morning.

Bureau of Meteorology forecaster Abrar Shabren says rainfall over the past 24 hours has done little to help.

"We did see some rainfall on the Erskine Creek fire near the Blue Mountains but it wasn't as much as we saw in the central and mid-north coast parts of the state and not enough to suppress fires," Mr Shabren said.

Winds switched around on Monday evening making firefighting tougher around the ACT and on the South Coast.

Mr Shabren said the change should bring cooler temperatures and lower humidity which would continue throughout the week. More rain is expected at the end of the week.

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Crews used more favourable conditions on Sunday to contain the Morton fire which has burnt more than 23,000 hectares in the Southern Highlands and the 334,000-hectare Dunns Road blaze in the Snowy Mountains.

Strong winds and high temperatures on Saturday night pushed the massive 177,000-hectare Border fire north towards Bega Valley while three separate blazes burning southwest of the region merged into one.

Bega Valley Shire Council Mayor Kristy McBain says the weekend losses will push the total number of properties destroyed in the Bega Valley to more than 400.

There are also unconfirmed reports five structures were lost when the out-of-control Clear Range blaze - created from embers that spread from the ACT's large Orroral Valley fire - flared up on Saturday night.