A bushfire burning at Tianjara was downgraded to advice on Thursday evening, but residents are being warned to monitor the changing conditions.
The fire broke out on Thursday morning and has burnt more than 3205 hectares. On Friday morning, it remains at advice level and is still burning out of control.
Spotting from the fire has been seen ahead of the main firefront.
Phil Paterson from the NSW Rural Fire Service said the fire was rapidly moving.
"We had a south-easterly wind come through the fireground which has sent the fire toward the north," he said.
Residents near the fire were doorknocked by fire crews early on Thursday. The fire was upgraded to an emergency warning level mid-morning on Thursday, but was downgraded to watch and act, and then advice later in the day.
Mr Paterson said conditions had been deteriorating throughout the day, although no properties were directly under threat.
Residents in Jerrawangola, Wandandian, Sussex Inlet, Swan Haven, Cudmirrah and Berrara have been advised to monitor the changing conditions and to follow their bushfire survival plan.
On Thursday, Mark Williams from the Shoalhaven Rural Fire Service said the fire was "growing exponentially" to the east of Wandandian and was expected to impact on properties to the west of the Princes Highway.
The NSW Rural Fire Service said the blaze may hit Wandandian and parts of the Princes Highway.
Access to Sussex Inlet may be affected.
EMERGENCY WARNING - Tianjara fire (Shoalhaven LGA)— NSW RFS (@NSWRFS) December 19, 2019
Fire is increasing. If you're in Jerrawangola & Wandandian, it's too late to leave. Seek shelter. If you're in Sussex Inlet, Swan Haven, Cudmirrah & Berrara, remain in place. Princes Hwy may be affected. #nswrfs#nswfires#alertpic.twitter.com/cIno997UVe
The fire has forced the closure of Wandean Road and Braidwood Road between Turpentine Road and Nerriga.
Smoke from the blaze is hitting areas around Braidwood Road and Sassafras.
The fire is also close to the former Tianjara artillery range, which contains large amounts of unexploded devices.
An evacuation centre has been set up at the St Georges Basin Country Club in Sanctuary Point.
The new blaze came as fire authorities had warned the Currowan fire on the South Coast, which has been burning for several weeks, could deteriorate.
Homes in the area were forecast to potentially come under threat from embers and fresh fire fronts.
NSW fire authorities singled out the Currowan fire, along with the Green Wattle Creek and Gospers Mountain fire, as the ones that could pose the most risk across the state on Thursday.
NSW Premier Gladys Berejiklian declared a state of emergency on Thursday for the next seven days with severe conditions forecast.
Temperatures across the region are forecast to be above 40 degrees and strong winds are also predicted.
A total fire ban has been declared across the ACT and NSW until midnight on Saturday.
The Currowan fire has forced the closure of the Kings Highway between Braidwood and Nelligen, along with Araluen Road between Moruya and Braidwood.
The Kings Highway has now been closed to drivers for five consecutive days.
Fire crews have said while fire activity has eased to the east of the Princes Highway, large parts of the blaze continue to burn.
Active fires are burning around Benandarah, Windywoppa, Currowan and to the north of the Kings Highway.
Waterbombing aircraft are being used to help control the blaze in the Morton National Park.
High fire danger has been forecast for the South Coast on Friday and conditions are set to deteriorate further on Saturday.
Fire crews have flagged Saturday as potentially being rated as catastrophic, the highest possible fire danger rating.