Over 500 wildfires burn in Western Canada as smoke covers Alberta, again

Dangerously poor air quality returned to Alberta’s major cities Thursday.

Thanks to smoke from fires burning in Alberta, British Columbia and the Northwest Territories, the skylines of both Edmonton and Calgary became shrouded in grey.

According to Environment and Natural Resources Canada (ENRC), both cities reached a 7 on the Air Quality Health Index (AQHI) Thursday, placing them in the "high risk" category. The AQHI is determined using measurements of ozone, nitrogen dioxide and fine particulate matter in a region, and assigns a score of 1 through 10+ depending on the level of air quality detected.

Connor ODonovan - Smoky Calgary skies
Connor ODonovan - Smoky Calgary skies

Smoky skies return to Calgary - Connor O'Donovan

The latest round of hazy air comes courtesy a recent shift in wind.

"It’s pushing a lot of stuff in the from the Northwest Territories, northern British Columbia and northern Alberta," said Alberta Wildfire Provincial Information officer Melissa Story.

"So now we’re starting to see the effects of the fire smoke down here in the Edmonton and Calgary areas."

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As of Thursday afternoon, there were 117 active wildfires in Alberta, 358 in British Columbia and 84 in the Northwest Territories.

Northern Alberta communities such as Fort McMurray, Fort Chipewyan and Fort McKay all reached 10+ on the AQHI Thursday, as more than 2300 firefighters from around the world battled the blazes.

Just 13 of Alberta's wildfires burned out of control Thursday, and the province has just one community, Fox Creek, listed under evacuation alert.

Story added that some of the aggravating factors seen this spring in Alberta, when around 35,000 people were displaced by the threat of fire, have eased.

"In terms of the conditions now compared to what they were, we’re seeing a bit more seasonal weather patterns. So, we’re seeing more reprieve from the rain, and not seeing the extreme windy conditions we had earlier," she said, adding that the fight is still far from over.

"We’ve been at it for months now, so folks are getting tired. We’re very grateful for the support we’re getting from out-of-province and around the world right now."

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ENRC forecasts that both Edmonton and Calgary, where the annual Calgary Stampede is underway, will again reach 7 on the AQHI Friday.

Stampede organizers said Thursday that they had no immediate plans to alter any events due to the smoke.

At AQHI levels of 7 and higher, ENRC recommends that the general population consider reducing strenuous outdoor activity if symptoms of irritation like sore throat occur, and that those with lung and heart conditions reduce or avoid it completely.

WATCH: What do those air quality numbers actually mean?

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