San Francisco Frontiers - Toronto air ranked among world's worst as wildfire smoke moves south

Toronto edged out the Democratic Republic of Congo's capital Kinshasa and New Delhi for air pollution, as wildfire smoke turned the skies a hazy yellowish-grey in Canada's largest city.

"The biggest contributor to Toronto's spike in air pollution right now is wildfires, though the higher than average temperatures are also playing a role," Armen Aradian of IQAir told AFP.

While this year's wildfire season has been fairly muted compared to the devastation caused in recent years, there are more than 800 active fires nationwide.

Smoke from blazes in northwestern Ontario has filtered down to Toronto, the provincial capital.

Local authorities have urged people to stay indoors, and summer camps have scrapped outdoor programming to guard children from the smoke.

City officials have also cancelled FIFA fan festival activities for today's semi-final match between England and Argentina.

Montreal saw a similar, though less severe impact from wildfires on Tuesday.

Canadians are enduring potentially hazardous air as a record-smashing North American heat wave persists.

Extreme heat and humidity in the Mountain West spilled over to the densely populated East Coast of the United States and Ontario.

The heat in Ontario is expected to ease by the weekend, but officials have warned of persistent risk from wildfires through the remaining summer months.

So far, Canadian wildfires have scorched 1.9 million hectares this year, an area nearly the size of Slovenia.

That damage remains far off the pace of 2023, Canada's worst wildfire season on record, when nearly 18 million hectares burned in the country.

V.Mitchell--SFF