Special weather alerts issued in Ontario for some of the worst air quality in the world

As Southern Ontario enjoys a very welcome midweek hit of summertime temperatures following an unseasonably chilly and dreary end to May, residents may notice that the sun appears to be working overtime to shine through a layer of haze carried in from the wildfires raging in B.C., Alberta, Saskatchewan and Manitoba.

The skies above the Toronto area started looking a little congested on Monday as smoke began making its entrance from the western provinces, where thousands of people are being evacuated and some companies are shutting down operations amid intensifying blazes.

As of Tuesday afternoon, 29 Ontario locales have been issued air quality warnings or special weather statements from Environment Canada due to the deteriorating conditions.

The alerts affect the western third of the province, including cities like Thunder Bay, which had an extremely dangerous level of pollutants that rated it as "hazardous" on the U.S. Air Quality Index this morning with a score of 635.

At the time of publication, this figure has thankfully dropped to 134, considered "unhealthy" — not ideal, but an improvement. Further north in Ontario, though, ratings are in the dangerous 500 levels in places like Kasabonika Lake First Nation. (By comparison, the worst air quality of any major city on the list right now, per IQAir, is Kuwait City with a score of 408.)

The impact of wildfire smoke on Thunder Bay. Photos taken less than a week apart
byu/i-love-big-birds inontario

Locals in and around the impacted regions have been cautioning others about the smog on social media, with multiple accounts and photos from Thunder Bay in particular popping up Tuesday. 

EnviroCan explains that "smoke is causing or expected to cause poor air quality and reduced visibility" in the northern city and "may remain in place for the next several days for some areas."

"As smoke levels increase, health risks increase. Limit time outdoors. Consider reducing or rescheduling outdoor sports, activities and events," the agency continues before advising of potential "mild and common" symptoms ranging from eye and throat irritation to coughs and headaches as a result of the present atmosphere.

This low-lying smoke could potentially make its way further east to significantly worsen air quality in the GTA, but at present, T.O. is only experiencing loftier pollutants. Environment Canada rates the city's air quality as a 4, on the lower end of a moderate risk, compared to Thunder Bay's level 8, or high risk, by the same metric.

As many will remember, Toronto moved to the top spot for having the worst air in the world at one point during summer 2023, thanks to smoke plumes from wildfires in northern Ontario and Quebec during what was, at the time, the worst wildfire season on record.