Smoke from wildfires is affecting air quality in parts of British Columbia even as fewer blazes are burning, a provincial fire official says.

Kevin Skrepnek of the B.C. Wildfire Service said 481 fires were still active in the province on Thursday, down from 550 blazes at the height of the fire season.

Newer fires have been smaller and cooler weather has helped firefighters, he said.

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“The worst is definitely over at this point. But there’s still a lot of work that remains to be done. A lot of large fires are still burning.”

The Tweedsmuir fire in the west-central region of British Columbia was the largest in the province on Thursday. The fire is a combination of blazes that cover about 3,000 square kilometres. The single largest fire this season was Alkali Lake, at more than 1,000 square km.

A record-setting 13,000 square km have been charred by wildfires this year, surpassing slightly more than 12,000 square km that burned during the 2017 season, although more people were forced from their homes last year.

A fire near Shovel Lake, which grew to more than 900 square km over the past month, is unlikely to grow any further, Mr. Skrepnek said.

Cooler and wetter weather means some campfire bans in effect across British Columbia could soon be lifted.

Mr. Skrepnek said more rain is critical.

“We need to see that widespread steady rain to hit the reset switch on the situation.”

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Environment Canada has forecast several days of rain starting Saturday in Prince George, Fort Nelson, Fort St. John, Kelowna and Grand Forks.

Metro Vancouver issued an air-quality advisory for Metro Vancouver and the Fraser Valley because of elevated concentrations of fine particulate matter from wildfire smoke in British Columbia and the Western United States.