B.C. community evacuates, A12 Haze across Canada,

OTTAWA — Air pollution from wildfires remained well above healthy levels across much of southern and northern Ontario and several communities in B.C. and Alberta on Thursday.

There may be some hope on the horizon after the number of fires burning across the country fell slightly, but forecasts suggest smoke warnings will remain in place in several provinces into the weekend.

The record-setting air pollution that blanketed Ottawa and much of eastern Ontario with a yellow-tinged haze on Wednesday had mostly cleared by Thursday morning, and the sun was even glimpsed briefly.

But farther south, toward the Greater Toronto Area and in areas around Sudbury and North Bay, the air quality remained poor. Environment Canada forecast very high-risk air quality in the GTA, southwestern Ontario and the Niagara region into Thursday night.

Health studies have linked wildfire smoke to serious health consequences including heart attacks, strokes and breathing problems, and the poor air quality has prompted cancellations or changes to outdoor activities as a result.

The Toronto District School Board joined several of its counterparts across the region in cancelling outdoor activities and moving recess inside for a second straight day Thursday. The Toronto Zoo also announced it would close early. Today and Saturday, most of Ontario should expect moderately bad air quality. At high risk, people are advised to reduce their outdoor activities, while at moderate risk the advice is to only consider doing so.

In Alberta, the worst air is near Fort Chipewyan, which remains under an evacuation order as a fire burns out of control. Wood Buffalo and Grande Prairie also have high-risk airquality forecasts. Moderately bad air quality is forecast for Edmonton and Calgary today.

The Canadian Interagency Forest Fire Centre said there were 431 fires burning on Thursday in nine provinces and two territories. That was down from 441 Wednesday, with Quebec extinguishing 10 fires since Wednesday morning.

The number of out-of-control fires also fell from 256 on Wednesday to 234 on Thursday, including a change in status for more than a dozen fires in Quebec.

The eastern United States has been seeing the effects from wildfire smoke drifting south, with cities including New York and Washington, D.C. issuing air quality warnings of their own.

The U.S. Federal Aviation Administration grounded flights out of Philadelphia International Airport on Thursday morning and slowed traffic to and from New York City-area airports as wildfire smoke reduced visibility.

More than 43,000 square kilometres have burned so far this year, making 2023 the second-worst year for fires on record.