Environment Canada warns of 'very poor' air quality as wildfire smoke hangs over Toronto

The broadcast lineament in Toronto is among the mop up in the domain Wednesday.

An orange-level air quality warning remained in effect for Toronto on Wednesday night due to heavy smoke conditions from wildfires.

"During heavy smoke conditions, everyone’s health is at risk regardless of their age or health status," the federal weather agency said in the warning.

Drifting smoke from forest fires in northwestern Ontario is causing "very poor" air quality and reduced visibility for much of southern Ontario, the federal weather agency says in the warning.

An air quality warning was first issued for the area Tuesday night. Conditions may last through to Friday morning, the agency says.

The warning came at the end of a three-day heat wave in the city. Environment Canada lifted its yellow-level heat warning just before 4 p.m. Wednesday.

Toronto ranked first in a list of the world's most polluted major cities as of Wednesday morning, according to a global ranking by IQAir, a Swiss air quality technology company. It later dropped to second place behind Kinshasa in the Democratic Republic of Congo.

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"The air quality values have spiked quite high due to the particulate matter from that forest fire smoke," said Environment Canada meteorologist Brian Owsiak.

He said the smoke will likely "flush" out with the shift in wind direction coming later in the week or during the weekend.

The presence of smoke is typical in Canada during wildfire season, said Eric Kennedy, an associate professor and expert on wildfire management at York University.

Environment Canada urged people to "reschedule or cancel" outdoor activities and to limit time outside.

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Meanwhile, FIFA World Cup watch parties for the Argentina-England match were cancelled at FIFA Fan Festival, Nathan Phillips Square and the University of Toronto due to the air quality warning.

All city-run outdoor pools were also closed mid-afternoon due to the air quality, the city said in a bulletin Wednesday afternoon. The city said later that they will remain closed Thursday.

Indoor recreation facilities are staying open as part of Toronto’s heat relief strategy.

CampTO trips and outdoor programs have also been cancelled, the city said.

Residents may experience symptoms such as eye, nose and throat irritation, headaches, chest pains or severe cough. Those more likely to be affected by smoke include seniors, pregnant people, young children, people with an existing health condition and people who work outdoors.

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While Wednesday wasn't as hot as Tuesday, Owsiak said morning temperatures started off at 26 C and would rise to a high of 33 C in Toronto, feeling closer to 36 C with humidity. Even after the sun goes down, the overnight low was expected to be 20 C Wednesday.

Mayor Olivia Chow said the city and Toronto Public Health are taking action to keep residents safe from the smoke and the heat by opening up six cleaner air spaces, including City Hall and Metro Hall.

The city also opened over 500 cooling spaces, including a 24-hour cooling space at 136 Spadina Road.

Chow said her "heart goes out to everyone" impacted by the wildfires, adding the city's public health agency is on standby to support people evacuating to Toronto.

"Together we look after each other, especially during challenging conditions like this," said Chow.

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They city's shelter system is opening additional temporary space for people living on the street.

While the heat warning for Toronto lifted Wednesday afternoon, excessive heat has blanketed the city since Monday.

Tuesday was the peak of a heat wave, when the temperature at Pearson airport reached 36.2 C by 4 p.m. The humidity made it feel closer to the mid-40s, Environment Canada said on its website.

Toronto came close to beating the highest temperature ever recorded for July 14 at Pearson airport, which was 36.7 C. The hottest day of 2026 so far approached that figure, when Canada Day saw a high of 36 C.

Heat, wildfire smoke combine to create dangerous conditions across southwestern Ontario

Wednesday was the 13th day this year that it was above 30 C in Toronto. Usually the city would register just seven days that hot by mid-July, says Environment Canada climatologist emeritus Dave Phillips.

The agency says there were 39 heat-related emergency room visits recorded during Toronto’s first heat event of the summer between June 30 and July 4.

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