Communities of concern to the RFS are: Dignams Creek, Coolagoltie, localities between Mogareeka and Bermagui, Candelo, Tantawangalo, Rocky Hall, Nethercote, Towamba, Burragate, Wyndham, Mt Darragh, New Buildings.

Evacuation centres are open at Bega Showground and Bermagui Surf Club, but residents should bring their own bedding. Plans are in place to open an evacuation centre in Merimbula if the need arises.

The Very High Fire Danger on Friday will move to a Severe Fire Danger on Saturday.

Mr Webster said the weather was "pretty much on forecast" and while an inversion layer over the region had been helping firefighting efforts, further west was still seeing "a lot of active fire".

"Today is not setting us up well for tomorrow," he said.

"People who've perhaps stayed put today, I'd really be urging that you consider moving very early tomorrow if not tonight.

"Those areas closest to these firegrounds are likely to see a lot of fire, and potentially fire moving around overnight too.

"We're not really expecting to see conditions ease much overnight, it's still going to be hot, windy.

"It will naturally abate a little bit into the evening, but as we've seen this season fires aren't really respecting nighttime that much."

Temperatures across the region were in their high 30s to early 40s on Friday with hotter expected for Saturday.

A council spokesperson said bad weather is expected to stay with us until at least midnight Saturday and into early Sunday, with variable winds with a north west and easterly influence strengthening.

"Weather and fire behaviour is increasingly unpredictable," they said.

Mr Webster said the advice was still if you were not prepare to stay and defend your life and home it was best to leave early.

"It's one of those days where we're finding it difficult to extinguish fire and we've got great big red trucks, so we've got a bit of a head start," he said.

"Only people that are prepared to the highest level should really consider staying, everyone else we recommend relocating to a safer place."

Council has asked residents to limit the use of town water as unattended sprinklers and unnecessary hosing down of houses and property has a significant impact on the water storage and water pressure available to fire fighters.

The Big Jack Mountain Fire was upgraded to Watch and Act in the afternoon with Mr Webster saying a "fairly significant column of fire" was developing.

"That is causing us some concerns this afternoon, it's going to be very difficult to bring it under any kind of suppression," he said.

"If you're still out there, please if you start to see burning material or embers, call Triple Zero.

"Any sign of spot fires taking hold or actual live embers, call Triple Zero."

NSW RFS said the fire is burning in the area north west of Big Jack Mountain Road around Cathcart Trig. Fire activity has increased near Mount Darragh Rd, west of Mt Darragh.

It has now crossed Mt Darragh Rd, and the road is closed from the intersection of New Buildings Rd, while Tantawangalo Mountain Rd is also closed.

RFS advice for Mt Darragh residents: Conditions are changing and fire activity has increased. Check and follow your Bush Fire Survival Plan and prepare for a bush fire in your area. If you do not have a plan know what you will do if the fire threatens. Leaving early is your safest option.

RFS advice for residents of Rocky Hall, New Buildings, Burragate, and Wyndham: Under forecast conditions, your safest option is to leave early. Consider relocating to coastal towns before conditions deteriorate. Know what you will do if the fire threatens. Also monitor major fire updates for Postmans Trail fire and Border Fire.

Mr Webster said there had been extra activity in the Border Fire in the afternoon.

He said it was burning about 6kms south west of New Buildings and he had been hearing reports of ash and burnt material landing at places like Burragate.

Mr Webster said the Postmans Track and Creewah Fires were effectively one fire now for all intents and purposes, but were perhaps not quite as active as what firefighters were seeing at Big Jack Mountain.

"But again that's a fire that's very difficult to contain," he said.

"People who know the area know the sort of terrain we're working in.

"It's really a case of just making sure we can keep people safe from that fire today."

The fire was also upgraded to Watch and Act on Friday afternoon.

Mr Webster said the RFS has still not heard of any reports of fire from the Werrri Berri section behind Bemboka.

"Along the coast there was some activity in the Bermagui, Coolagolite area this morning," he said.

"But fortunately crews have had a good success there and conditions are much more friendly to firefighters on the coast than further inland.

"It's still challenging, but not as bad as out west."

Stay up to date on bush fires in your area by checking the NSW RFS website, listening to your local radio station, or by calling the NSW RFS Bush Fire Information Line on 1800 679 737.