The big North Black Range fire east of Canberra was expected to continue through Sunday as the hostile windy weather picked up after overnight easing.
On Saturday, the area of the fire had expanded to more than 20,000 hectares as gusty winds took it over fire breaks.
A spokesman for the RFS said that they were expecting "another challenging day" on Sunday, but with the hope that the weather would finally move against the fire on Monday.
On Sunday morning, the fire had not moved significantly overnight. Winds are expected to strengthen from mid-morning, increasing the fire activity.
The advice for Sunday was that people south of the Cooma Road near Braidwood should be ready and well prepared if they were going to stay and defend their property, "or have a plan to leave early."
The south east boundary of the fire near Jembaicumbene and Majors Creek could pose a threat as winds increase.
Fire crews were ready to be deployed again after a tough day in unpredictable, gusty conditions on Saturday. The fire broke through several containment lines.
Local firefighters were bolstered by reinforcements from the ACT, the Southern Tablelands, Illawarra and other regions. A hundred firefighters were involved.
A picture of the fierceness of the challenge emerged from stunned local people who had fought the flames on Friday night as the blaze surrounded their properties.
The Lans family - father, Ben, and brothers and sister, Rob, Matt and Raewyn - told how the fire was on three sides and within 20 metres of the home they had built with their own hands in deep forest.
They had planned to leave the property but realised that they had made the decision too late so had to stay and defend it.
"We had a back up generator and we just got the sprinklers going," Rob Lans said.
They had bore water and a water system on the roof to prevent it catching light.
"It was very frightening. It was terrifying," they said. The heat was like a hot oven.
A fire truck arrived at the crucial moment. "The fire captain from Carwoola was the calmest man in a crisis I've met," said the father, Ben Lans. "He just exuded confidence and control."
Throughout the day, property owners watched the smoke as it moved unpredictably around the landscape, aircraft fire-bombing different outbreaks.
Farmers helped neighbours steer cattle to safe paddocks. Dave Bopping who has 60 head of cattle on Major Creek Road said, "I've prepared a fire-fighting tank with water and pumps and hoses to prepare for whatever comes.
He rode his motorbike along ridges to review the threat. "It's got really windy here so I've come up to see what's happening.
"I noticed my neighbour was moving his cattle so I went and helped him move his cattle into yards on his property, then went back and secured my own cattle and put them in a paddock where there's no fuel for the fire.
"Now it's a watch and wait. But the firies have done an outstanding job to control the outbreaks."
Nobody could remember a bush fire this fierce or this early in the season.
"This is the closest a bush fire has been as long as I can remember and I've been here all my life," said Mr Bopping who is just short of 60.