Toronto engulfed by wildfire smoke as US cities threatened | Climate News
Toronto Ranks as World’s Most Polluted City Amid Wildfire Smoke
Published July 16, 2026
Toronto has been identified as having the worst air quality among major cities globally, surpassed only by Kinshasa in the Democratic Republic of the Congo and New Delhi, India, according to a report by IQAir, a Swiss air quality technology firm. The ranking comes as smoke from ongoing wildfires in northwestern Ontario blankets the city and spreads into parts of the northeastern United States, prompting multiple health advisories and evacuations.
On Wednesday, Environment Canada issued an Air Quality Health Index reading of 10+, categorized as “very high risk,” for Toronto. Conditions are expected to remain hazardous through Thursday night.
Despite this year’s wildfire season being less intense than in previous years, over 800 active fires are currently burning nationwide, primarily impacting sparsely populated areas hundreds of miles from Toronto. Armen Araradian of IQAir attributed the increase in air pollution to both the wildfires and unseasonably high temperatures.
In a notable incident, Canadian National Railway suspended operations near Armstrong, Ontario, after a video circulated on social media showing a train surrounded by fire. Residents and employees in the area were evacuated as a precautionary measure.
The smoke’s impact has reached the United States, particularly affecting air quality in Pennsylvania, New York, Connecticut, Massachusetts, Maine, and New Hampshire. In New York City, officials have issued alerts warning residents to limit strenuous outdoor activities and take adequate breaks if outside.
Dan Westervelt, an associate research professor at Columbia University, noted the potential for worsening conditions in the coming days. “We probably haven’t seen the worst of it yet for New York City,” he stated.
As environmental conditions remain precarious, over 80,000 attendees are expected at the FIFA World Cup final in New Jersey this Sunday, with an additional 50,000 planning to watch the event from Central Park, where hazy skies have been reported. Governor Kathy Hochul urged those with health concerns to exercise caution.
The Canadian government has recognized the slower start to the current wildfire season compared to 2023 and 2025, which were among the worst years recorded. However, officials have warned that the risk remains elevated due to warmer-than-normal temperatures.
On Wednesday, 835 active fires were reported across Canada, with 112 of those classified as out of control, primarily in Manitoba, Saskatchewan, and Ontario. These fires have consumed approximately 1.9 million hectares (4.7 million acres) so far this year.
Greg Evans, a professor of chemical engineering and applied chemistry at the University of Toronto, expressed concern over the dual threat of extreme heat and wildfire smoke. “I expect that this will occur more frequently over the coming decades,” he cautioned, emphasizing the need for cities and residents to prepare for similar situations in the future.
