Firefighters battling the North Black Range fire are trying to control as much of it as they can ahead of a "peak" in dangerous conditions on Thursday.
NSW Rural Fire Service Lake George district officer Darren Marks said crews had "reasonable" success in containing the eastern border of the blaze near Braidwood on Tuesday.
Braidwood Preschool, Braidwood Central School and St Bede's Primary School will reopen on Wednesday after closing for two days, although parents have been urged to monitor fire conditions.
Mr Marks said firefighters had contained the blaze in the Bombay Road area.
Kings Highway closed for more than an hour near Braidwood as the fire jumped containment lines on Tuesday.
Firefighters brought the blaze back under control after it broke out and ran 500 metres towards the highway in the area of Columbo Road and Black Sally Lane.
A 16km stretch of Kings Highway was closed for about 90 minutes until 4.30pm between Foxs Elbow Road and an area just north of Braidwood township.
Firefighters escalated their fire warning to "watch and act" about 3pm as they worked to contain the fire, which has burnt more than 24,000 hectares over the last week.
They downgraded it to an "advice" level warning at 4.30pm as they stopped the fire's run towards the highway and conditions eased.
The blaze is burning west of Braidwood, between Forbes Creek and Cooma Road, and intensified throughout Tuesday with strong winds before conditions eased.
Mr Marks said firefighters expected another day of similar conditions before a "peak for danger" on Thursday.
Firefighters would also struggle to contain the fire in Tallaganda National Park, and especially at Lowden Forest Park.
NSW Rural Fire Service warned westerly winds this week would create a risk the fire will spread and spot, particularly around Mount Elrington Road and Bendoura.
It has also singled out Columbo Road and Wallaces Gap Road as areas of risk.
Firefighters have urged people living in the area of Forbes Creek, Butmaroo, Watsons Road and Columbo Road to activate their bush fire survival plan and follow the advice of firefighters.
NSW Rural Fire Service has also warned residents at Mount Elrington Road, Jembaicumbene Creek, Bendoura/Wallaces Gap Road, Majors Creek and Reidsdale, and Little Bombay and Bombay, including Jinglemoney Road and Gilberts Lane, to monitor conditions.
People living at Farringdon, Harolds Cross, Hoskinstown, Foxs Elbow, Manar Road, Warri and Braidwood are urged to continue monitoring the situation, and to act now to protect stock and animals.
Tallaganda National Park, State Conservation Area and State Forest are closed, as are all roads in the area including Mulloon Fire Trail and Lowden Road.
Firefighters have expressed concern the North Black Range fire could link with the Currowan fire burning on the South Coast.