The air quality in Toronto has become so polluted due to smoke from forest fires in Quebec and Ontario that strenuous outdoor activities could leave you coughing and with an itchy throat.

Environment Canada says that air quality in the city has reached level 7 on its index – which the federal weather agency said presents a “high risk.”

An air quality advisory has been in effect for Toronto since Monday and the smell of smoke and sight of haze has been present ever since.

As of 5:30 p.m. the air quality was downgraded to level 6, which is considered a “moderate risk,” and is expected to remain at that risk level over night.

However, smoke density is forecast to intensify Thursday morning and bring with it even worse air quality which will push the risk level to 9 by Thursday afternoon.

“Consider reducing or rescheduling strenuous activities outdoors if you experience symptoms such as coughing and throat irritation,” the agency advises when air quality risk levels are between 7 and 10.

At the time of writing, the World Air Quality Index shows that Toronto currently ranks as having the third-worst air quality in the world.

Meanwhile, the Toronto Blue Jays have announced that Thursday night's game will be played under a closed roof due to the smoky conditions.

Toronto smog

On Tuesday, a number of fire bans were issued across parts of the Greater Toronto Area and several school boards, including the Toronto District School Board, announced that outdoor events planned for Wednesday and Thursday had been rescheduled or moved indoors.

The City of Hamilton is the latest municipality to issue a fire ban on Wednesday, meaning that even individuals with Open Air Burning Permits are not allowed to start an open flame.

As well, officials with Niagara Falls Tourism noted it is pausing its firework program due to the impact of the wildfires.

"Air quality conditions will be reviewed on a daily basis, with updated status reports issued at noon," they said in a statement.

Environment Canada is suggesting that if you need to spend time outdoors, consider wearing a face mask to reduce the exposure to smoke particles which “generally pose the greatest risk to health.”

"It's a particular concern for people with lung disease, such as asthma or heart disease, older adults, children, pregnant people, and people who work outdoors," Trudy Kidd, a warning preparedness meteorologist at Environment Canada, told CTV News Toronto in an interview.

"Those populations can consider stopping outdoor activities, they can contact their health-care provider if [they] experience shortness of breath...wheezing, including asthma attacks, severe cough, dizziness or chest pain," she said.

The smoke from the wildfires, which can be seen from as far away as New York City, will likely continue into the weekend, according to Environment Canada.

There are currently more than 100 fires burning in Quebec and more than 50 burning in northeastern Ontario. 

Ontario smoke forecast


Kidd said a high-pressure, “stagnant weather pattern” that’s “stuck on top” of the city is contributing to the lingering smoke in the air.

Before the air quality improves, Kidd said, one of two things needs to happen.

“You need to either solve the source of the issue, or the weather pattern needs to change,” she said, adding that the latter is a more likely scenario.

“The wind direction needs to come from an area of better air quality. So right now, we're getting winds from the northeast. And that's bringing in the fires from the north and northeast.”

Looking ahead to the weekend, Kidd said she expects a low-pressure system to move into southwestern Ontario likely by Sunday which will bring with it cleaner air less contaminated with smoke particulate.

“So I'm hoping that we all get a breath of fresh air on the weekend,” she said.