A large, out-of-control bushfire continued to burn near Bega on Wednesday evening despite easing conditions, with the NSW Rural Fire Service (RFS) saying it would monitor the blaze overnight.

Key points: Strong winds are fanning two large fires, one near Ulladulla and another near Bega

Strong winds are fanning two large fires, one near Ulladulla and another near Bega A blaze in north Nowra has been downgraded

A blaze in north Nowra has been downgraded Conditions are dry — last week, 100 per cent of NSW was declared in drought

Conditions are dry — last week, 100 per cent of NSW was declared in drought Tune in to ABC Illawarra for live updates

It was a chaotic day for authorities in the state, who have issued emergency warnings for several bushfires.

On Wednesday night, the blaze near Bega was threatening properties and some people had been told it was "too late to leave".

The fire had blackened 2,300 hectares of land — much of it inaccessible — but it was downgraded to watch and act level before 8:00pm.

Difficult terrain and erratic winds had made the situation more challenging for emergency crews.

"Firefighters will remain on scene throughout the night to slow the spread of the fire and protect isolated rural properties that may be impacted," the RFS said.

Two other fires — in Budawang National Park near Ulladulla and Nowra — also contributed to a hectic day for crews.

The fire at Mount Kingiman, near Ulladulla, burnt through 1,156 hectares and by Wednesday evening was downgraded to watch and act.

The fire near Nowra destroyed outbuildings and forced homes to be evacuated, however the threat eased in the afternoon.

NSW RFS Deputy Commissioner Rob Rogers said the fires at both Bega and Ulladulla were "quite big" and would stay uncontained for "some time".

"It'll be days and days to try and get containment of both of those fires," he said.

"We're still expecting difficult conditions right into tomorrow, and then we're concerned about a return to gusty conditions on Saturday when most of these fires will still be burning."

This structure near Bomaderry was destroyed by the blaze. ( ABC News )

Residents told to look out for embers

The blaze at Yankees Gap Road, north-west of Bega, was fanned by strong winds as conditions deteriorated in the afternoon.

It also produced large amounts of smoke, the RFS said.

Despite the easing of conditions, firefighters said embers may be blown well ahead of the fire, creating spot fires that could threaten properties.

The Snowy Mountains Highway was closed between Kameruka Lane and the Princes Highway.

Smoke from a large bushfire burning in the Bega Valley. ( Twitter: @danstrickaus )

No homes have been destroyed in any of the fires.

The RFS said 33 waterbombers were flying overhead to help the 870 firefighters with 270 fire trucks on the ground at the blazes across the state.

Nowra, Ulladulla threat eases

Earlier, dozens of fire trucks lined streets as people covered their faces at Bomaderry, near Nowra, as they tried to avoid breathing the plumes of smoke that were rising above homes.

Authorities clambered over fences in a bid to alert local residents about the danger.

That blaze is still burning out of control in the area of Woodstock Road, west of Burrill Lake.

The RFS said this evening it was moving in a south-easterly direction towards Burrill Lake.

The threat to properties in the area has eased and some residents may be able to return to their properties on the direction of firefighters.

However, the RFS warned there was still a "significant" amount of fire activity and crews would assess containment options, including backburning.

A police officer helps people evacuate near Nowra. ( ABC News )

Conditions in NSW are dry; last week 100 per cent of the state was declared either "in drought" or "drought affected".

Mr Rogers said the drought was making a huge difference for firefighters.

"We do get fires in August, but the dig difference is 100 per cent of the state is in drought and these winds are making the fires so difficult to supress," he said.

"It is a really early start to these severe fires, and it's only really been three months since the last serious fire we had, which was in April."

There is a total fire ban in place for Sydney, Illawarra and the Hunter Valley.