8pm UPDATE: More than 150 firefighters are continuing to battle the blaze at Wandanadian, which has destroyed 6000 hectares of bushland.
The Princes Highway has been closed for short periods throughout the day as fire crews conduct backburning operations.
Sussex Inlet Road is open to all traffic, however motorists are asked to be mindful of firefighters in the area and drive to the conditions. Braidwood Road, Turpentine Road, Wandean Road and Twelve Mile Peg are also closed.
6pm UPDATE: More than 130 firefighters are continuing to battle the blaze burning 12 kilometres west of Sussex Inlet, which has destroyed more than 5800 hectares.
The fire on the west side of Princes Highway has burnt close to three properties and crews have put in back burns to protect them in Wandandian.
Sussex Inlet and Wandandian may be further impacted tomorrow and Saturday with the onset of higher temperatures and stronger winds.
The Princes Highway remains open at this point.
1.40pm UPDATE: The Princes Highway has reopened. However, traffic remains heavy and motorists are advised to expect significant delays. Police are on site managing traffic.
11.40am UPDATE: The Princes Highway remains closed between Sussex Inlet Road and Bendalong Road as firefighters carry out back-burning operations along the road.
The Wandandian fire is still out of control with more than 80 firefighters continuing to battle the blaze.
8.30am UPDATE: More than 80 firefighters are continuing to battle the fire burning south of Sussex Inlet.
The blaze, which is still out of control, has destroyed more than 5700 hectares of bushland.
Fire crews spent the night back-burning in the area in an attempt to contain the fire.
The Princes Highway is currently closed to traffic, due to heavy smoke in the area.
6am: Grey skies were a welcome sign for those fighting a bushfire raging near Wandandian yesterday.
The milder conditions gave Rural Fire Service (RFS) volunteers some respite, but the blaze was still burning out of control last night.
Fifty Illawarra firefighters yesterday had pitched in to relieve weary volunteers battling the fire.
By late yesterday afternoon the fire had a 44-kilometre perimeter and had consumed more than 4000 hectares of bushland.
The fire, which started 1.5 kilometres west of Wandandian on Monday night, crossed the Princes Highway on Tuesday night and continued to burn to the south of Sussex Inlet yesterday.
Last night the RFS was concerned Wandandian could come under threat if the fire was pushed along by strong winds.
RFS and Fire and Rescue NSW firefighters were deployed along the Sussex Inlet Road to protect properties.
More than 120 firefighters and 21 trucks were working to contain the fire.
Mount St Thomas resident Angela Boyd-Skinner and her family were evacuated from the Bendalong Point Tourist Park after the RFS issued an emergency warning on Tuesday night.
After spending the night with family in Ulladulla, Ms Boyd-Skinner was yesterday waiting for the Princes Highway to reopen so she could head home to the Illawarra.
Ms Boyd-Skinner said Milton was teeming with people wandering around in limbo, waiting for the chance to head north.
The Princes Highway between Bendalong Road and Wandean Road was eventually reopened about 11.40am after closing almost 20 hours earlier.
Peter Christopher, who made the eerie journey along the highway yesterday, told the Mercury of the devastating destruction and charred landscape.
He said police were stopping traffic just before Bendalong and allowing 50 to 100 vehicles through at a time, travelling at 60km/h under police escort.
"There's burnt-out bush all around," he said.
"There are melted road signs. I can see a farmhouse still standing, and horses still standing but the bush is really badly burned on both sides of the highway.
"The bush and grass is absolutely destroyed, but houses are OK. [The firefighters] have done a great job."
A catastrophic fire-danger rating for the Illawarra and Shoalhaven was yesterday downgraded to high.
Blissfully moderate conditions settled over the region, in stark contrast to Tuesday's suffocating heat.
The highest temperature recorded at Kiama yesterday was half that of the previous day.
In contrast to the steamy 42 degrees recorded on Tuesday, the mercury just scraped above 20 degrees.
It was a similar story at Bellambi and Albion Park, where temperatures remained in the low 20s, a far cry from 43.1 degrees the previous day.