Smoke from wildfires raging in Washington state has drifted north, blanketing much of southern British Columbia in a thick haze.
Winds drove smoke from several wildfires south of the border into the province over the weekend, resulting in poor visibility and air quality issues, the B.C. Wildfire Service said in a release.
A series of wildfires in Washington state has grown to 968 square kilometres, and includes the Stickpin fire burning about 4.5 kilometres south of the Canada-U.S. border.
B.C. fire crews, including 33 fire personnel, three officers and two pieces of heavy machinery, crossed into Washington state on Sunday to help American crews fight the blaze.
Fire information officer Fanny Bernard said the Canadians will be responsible for a northeastern branch of the 192-square-kilometre fire.
The fire is still burning out of control, but Ms. Bernard said it isn't threatening to cross into Canada anytime soon.
"It's holding steady away from the border," she said. "There's no significant growth towards the north."
Another fire scorched the area in 2003, which is helping prevent the flames from spreading north, Ms. Bernard explained.
"Burns like that remove a lot of fuel from the fire's path, so that would have played a very large role in slowing it down," she said.
Still, the Washington fires have created problems in B.C. as smoke drifts north, including air quality warnings.
Environment Canada issued an air quality alert for several southern regions Sunday, warning there are high levels of fine particulate matter in the air and cautioning people to avoid strenuous activity outdoors.
Metro Vancouver also issued an air quality advisory for central and eastern Fraser Valley.
Provincial Fire Information Officer Kevin Skrepnek said the smoke makes it more difficult for crews to battle the 184 fires currently burning across the province.
Reduced visibility means aircraft have been grounded and the thick haze makes it more difficult to spot new fires, Skrepnek said.
While the haze is expected to linger over B.C. for the next few days, officials say a massive cloud of smoke was expected to lift over Washington later Sunday.
But Suzanne Flory, a spokeswoman for the U.S. Forest Service and the Rocky Mountain Incident Management team, said that may not be good news, because it could cause the fire to become more erratic and intense.
"It's like a flue opening in a fireplace," Ms. Flory explained. "Smoke serves as a cap on the fire."
With files from The Associated Press