The largest fire burning in the Cariboo has grown by almost 3,500 hectares in the past day.

The Flat Lake Fire near 70 Mile House is now 19,247 hectares in size, according to an update Tuesday morning. The update says the change is size is due to better mapping and doesn’t include actual growth from Monday, which means the blaze will increase in size in a later update.

In a virtual update with members of the Cariboo Regional District, BC Wildfire Service incident commander Kyle Young said growth was on the fire’s southeast flank, closest to part of Highway 97. That’s where fire crews did controlled burns on Monday to remove fuels between the fire’s edge and a fireguard created by crews.

“We need to really try to find an anchor point and try and get around that southeast corner. And stop, or limit, the growth that we’re experiencing there. Just with the predominant winds and what we’re seeing, that’s been our problem area for the last few days.”

A glimmer of good news from Young was that the weather has been more cooperative, with overnight lows dropping to about two degrees Celsius at some parts of the fire and relative humidity of 100 per cent after dusk.

“As the day progresses and we pick up heat, that’s when we start to see an increase in fire behaviour, in the late afternoon.”

He says there are guards in place on the fire’s northeast flank, and says there’s no concern right now for safety in the District of 100 Mile House.

100 Mile is on evacuation alert from the fire, and so are more than 3,000 other properties south of the community. Another 1,074 properties in the Cariboo Regional District are also on evacuation order from that blaze. A full map of areas affected can be found here.

The Flat Lake fire broke out on July 8, and grew rapidly about five days after it started. It’s the largest of 18 fires in Cariboo Fire Centre as of Tuesday morning.