Wildfire smoke chokes Toronto, New York, Washington

Dense smoke from hundreds of wildfires burning across Canada has severely affected air quality in parts of

Dense smoke from hundreds of wildfires burning across Canada has severely affected air quality in parts of Canada and the United States, placing Toronto, New York City and Washington, D.C. among the world’s most polluted cities.

Authorities in both countries have issued health advisories, urging residents to limit outdoor activities as hazardous smoke continues to spread across the region.

According to Canadian wildfire officials, nearly 1,000 wildfires are currently active across the country, with a large number burning in Ontario. Many of the blazes remain out of control, forcing evacuations and causing significant damage to homes, forests and public infrastructure.

One of the worst-hit areas is the Namaygoosisagagun First Nation in northern Ontario, where officials said the community suffered extensive destruction after fast-moving flames swept through the area. Residents were forced to evacuate with little warning, although no deaths were reported.

Smoke from the fires has travelled hundreds of kilometres, reducing visibility and pushing dangerous levels of fine particulate pollution into major cities across eastern North America.

Health officials warned that wildfire smoke contains microscopic particles that can penetrate deep into the lungs and worsen respiratory and heart conditions. Children, older adults and people with existing health problems have been advised to remain indoors, avoid strenuous outdoor activities and wear certified N95 masks if they must go outside.

Meteorologists said prolonged hot and dry weather, combined with below-average rainfall, created ideal conditions for the fires to spread. They added that changing wind patterns carried the smoke south toward heavily populated areas in the United States.

Canadian authorities said fire activity in parts of Ontario has begun to slow, raising hopes that air quality will gradually improve as weather conditions change and rainfall moves into the region.

The wildfire smoke has also triggered political tensions between the two neighbouring countries. US President Donald Trump criticised Canada over the continuing smoke crossing the border and threatened new tariffs, claiming the pollution was harming Americans.

Canadian leaders rejected the criticism, saying massive firefighting operations are underway and stressing that wildfire smoke is driven by weather conditions rather than national borders. They also pointed to previous occasions when Canadian crews helped battle major wildfires in the United States.

Meanwhile, concerns were also raised about air quality ahead of the FIFA World Cup final in New Jersey. However, weather forecasters expect improving conditions before the match as rainfall and shifting winds help clear the smoke.