As far as big cities go, Montreal has the worst air quality in the world on Sunday, according to a website that tracks air quality indexes (AQIs) across the globe.

In IQAir's ranking of major cities most affected by pollution, Montreal scored number one Sunday morning with an AQI of 230, followed by Kuwait City (221) and Tehran, Iran (169). Montreal's rating went as high as 243 on the Switzerland-based company's website.

The smog is a product of wildfires in northern Quebec, 80 of which are currently burning. Winds shifted to the northeast Monday evening, blanketing parts of southern Quebec in smoke. 

Environment and Climate Change Canada (ECCC) says air quality in the metropolis is "high risk" and cautions people to reduce their exposure as much as possible.

"People who have a lung disease (such as asthma) or a heart disease, the elderly, children, pregnant women and people who work outdoors are more likely to feel the effects of smoke on their health," the ECCC smog warning reads.

Smog warnings were also issued in several other parts of Quebec, including Laval, Longueuil, Trois-Rivières, and Quebec City. 

The weather agency recommends keeping the windows shut to preserve air quality indoors.

Montreal smog


The City of Montreal cancelled all outdoor cultural activities and ordered all outdoor sports facilities, including pools and wading pools, to close until noon on Monday, according to a tweet issued at 4:17 p.m. Sunday.

"Please stay indoors where possible," the city also said, adding in a news release that officials would reassess the situation on Monday.

Sidonie Pénicaud, a physician in environmental and occupational health at Montreal public health, said the air quality in Montreal on Sunday "is quite extreme."

She said common symptoms can include itchy eyes, an ithcy throat, and coughing. More vulnerable people can experience more severe effects, like difficulty breathing.

Medical and cloth masks don't work well, she said, on smoggy days to filter out pollutants "because they're very, very fine."

"Masks that can work can be the N95 but even then you do want the mask to have a very good seal on your face. Just buying a random mask, you may not get that good seal. The thing, really, to do is to avoid going outside," Pénicaud said in an interview. 

"If you were planning on going for a run or a whole day of outside activities to push it back to another day because working out outside … you breathe more, you breathe more air quicker, so there's more pollution that goes into your lungs quickly."

montreal smog

She said it would be ideal for people to keep their windows closed at home but realizes the summer heat can make that a challenge for some. Vulnerable people should go to indoor spaces with air conditioning if they can.


More information about protecting yourself from smog is available on Montreal public health's website


Some people who decided to venture outside Sunday chose to wear a face mask, including Dominic Holtappels who used an N95 mask to help cope with the poor air.

Deb Langelier said she also wore a face mask for the first time in a long while.

"It's affecting us in the sense that we're probably not going to walk up Mount Royal or Royal because of the air quality," she said. "We feel bad for the folks that are actually in the fire areas, you know. This is just an inconvenience."

Others were surprised just as much as they were concerned to see how bad the air quality was in the city.

"It's really sad and unsettling and is a sign that we should all be paying attention to the energy we're using and the resources we're expending and try to limit the extent of climate change," said Joel Abramovitz.

"It just burns the nose, burns the throat," said NDG resident Simon Benoit.

Milenko Petrovich and his son, Milan, often run to the Summit Lookout in Westmount but decided to put off their exercise on Sunday and drive there instead.

"We never saw this before, especially not here, we are running here frequently but not today," Milenko said.

"It's very hard to breathe," his son added.

The smog forced the cancellation of Sunday's half Ironman race in Mont-Tremblant.

Smog warning Quebec


Montreal got a wash of showers early Saturday evening. That rain broke by Sunday morning. Smoke will hang under sunny skies throughout the day with a forecasted high of 30 C.

The forests fires in the province continued to bring significant amounts of smoke over Montreal late Sunday afternoon. Air quality remained very poor but improvement will be felt as soon as noon Monday. 

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Environment and Climate Change Canada issued a special weather statement for Montreal and surrounding regions warning of possible thundershowers on Monday.

"Rainfall amounts from 20 to 40 millimetres are expected locally on Monday, however amounts could exceed 50 millimetres locally in thunderstorms," reads part of the special weather statement.

Showers are expected throughout the week as well. Temperatures should maintain a steady in the low to mid-20s. 

With files from CTV News Montreal's Lise McAuley and Olivia O'Malley