British Columbia

Air quality advisory issued for Metro Vancouver and Fraser Valley due to U.S. wildfires

Temperatures are rising and the haze has returned across the province, blowing in from fires in the United States and causing health warnings across much of southern B.C.

Temperatures break records as haze and heat blanket the province

Several times this summer, haze from wildfires has blanketed Metro Vancouver — pictured above on July 18, 2017 On Tuesday, Environment Canada issued another air quality advisory. (Tamara Baluja/CBC News)

Temperatures are rising and the haze has returned across the province, blowing in from fires in the United States and causing health warnings across much of southern B.C.

An air quality advisory was issued for Metro Vancouver and the Fraser Valley Tuesday advising residents to avoid strenuous outdoor activity.

Residents in the B.C. Interior and the Kootenays are also being cautioned about the smoky conditions.

"The visible haze that we are seeing today has been almost entirely due to smoke that has been transported all the way from fires in northern California and southern Oregon, maybe with a little bit of smoke from some fires in Washington," said Francis Ries, the senior project engineer in Metro Vancouver's air quality and climate change division.

Fine particles and ozone

Ries told CBC's On The Coast guest host Gloria Macarenko that the high concentrations of fine particulate matter and ground-level ozone in the air are similar to the smoky conditions from last month.

"This is absolutely the same thing," Ries said. "Whenever we have these wildfire-related advisories, it's the visible smoke and the particles that are smaller than we can see that are of concern."

Ground-level ozone, unlike particulate matter, is not transported over distance. It's formed in the air from a chemical reaction driven by the sun and caused by hot weather, Ries said.

Record breaking heat

Alyssa Charbonneau, a meteorologist with Environment Canada, said temperatures broke records in some part of the province Tuesday. At the Vancouver International Airport, temperatures reached 29 C — the previous record from 1967 was 28 C.

"It is definitely a hot one," Charbonneau said. "But for anyone looking for relief from the heat, the good news is it's not much longer."

She said marine air is expected to move in Tuesday night, dropping temperatures and bringing clearing winds over the next couple of days.

With files from On The Coast

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