Toronto records world's worst air quality as Canadian wildfire smoke spreads.
Over 835 wildfires burn across Canada, with 112 remaining out of control.
Wildfire smoke disrupts World Cup events and affects air quality across North America.
Toronto recorded the worst air quality globally on Wednesday as smoke from active wildfires across northwestern Ontario darkened the sky. The toxic haze prompted authorities to warn residents and urge them to limit outdoor activities.
Environment Canada stated that the Air Quality Health Index reached 10+, classifying it as a "very high risk" event. These hazardous conditions are expected to persist through Thursday night, Reuters reported. The wildfires are raging through sparsely populated areas hundreds of miles from Toronto, sending smoke over a wide area without directly threatening cities.
Swiss air quality technology company IQAir ranked Toronto as having the worst air quality globally, surpassing Kinshasa and Delhi. New York City ranked No. 5.
The City of Toronto cancelled the FIFA Fan Festival and the England-Argentina World Cup watch party at Nathan Phillips Square because of the poor air quality.
Impact on the US
New York City began feeling the effects days before neighbouring New Jersey hosts the World Cup final on Sunday. Local authorities warned residents as air quality reached an unhealthy level, urging them to reduce strenuous outdoor activity and take extra breaks on Wednesday and Thursday.
The National Weather Service stated that smoke could linger into the end of the week. Wildfire smoke from northern Canada has been a common summer occurrence across wide swaths of the US in recent years.
"We probably haven't seen the worst of it yet for New York City. We probably haven't seen the worst of it yet for the Great Lakes and upstate and New England yet either," Dan Westervelt, Lamont associate research professor at Columbia University, told Reuters.
New York Governor Kathy Hochul warned on social media that smoke and haze from Canadian wildfires were creating unhealthy air conditions across the state. She encouraged people, especially those with health conditions, to exercise caution.
More than 80,000 people are expected to attend the World Cup final at an open-air stadium in New Jersey on Sunday. Another 50,000 plan to watch the game from Central Park in Manhattan, where skies appeared hazy.
Wildfire Scope and Rescues
Some 835 active fires were burning in Canada on Wednesday and 112 were considered out of control, the government stated. So far, 1.9mn hectares (4.7mn acres) have burned. Most of the fires were in the central provinces of Manitoba, Saskatchewan and Ontario.
A video that went viral on social media showed a Canadian National train surrounded by fire near Armstrong, Ontario. Canadian National suspended rail operations near Armstrong, more than 500 km (310 miles) north of Toronto, as a precaution. The railroad operator stated that it evacuated employees and residents of Armstrong on Monday night.
Fires trapped two small groups of children from Minnesota who were in the Canadian wilderness on a camping trip organised by the YMCA, a worldwide Christian youth association. The Minnesota Star Tribune reported this on Wednesday, citing a YMCA official. One of the groups was evacuated by helicopter in coordination with the Canadian military, the newspaper reported.
"Both groups have been rescued and are on their way back home to safety," Minnesota Governor Tim Walz wrote on X.
Climate Context and Future
The Government of Canada stated that the wildfire season began more slowly in 2026 than in 2023 or 2025 — the two worst seasons for wildfires — but warned that fires were likely due to warmer-than-usual temperatures across the country.
Greg Evans, professor of chemical engineering and applied chemistry at the University of Toronto, said Toronto had been simultaneously hit with severe heat and wildfire smoke. "I expect that this will occur more frequently over the coming decades so cities and residents need to prepare for this in the future," Evans said.
Toronto resident Paula Oreskovich said she noticed the haze and smell of smoke when she stepped outside in the morning. She said the poor air quality was concerning, particularly as wildfire smoke has become a recurring feature of recent summers. "I think you have to be silly if you're not going to be concerned about climate change. It's definitely here, it's definitely happening, and it's happening globally," Oreskovich said.
