Smoke from Canadian wildfires triggers air quality alerts in over 20 U.S. states

Millions of Americans are now under air‑quality alerts that stretch from Minnesota to New York, as authorities in more than 20 states urge residents to stay indoors. The alerts come after smoke from a swarm of wildfires in south‑central Canada and Minnesota has drifted across the continent, turning clear skies into a hazy blanket that threatens public health.

The haze originates from over 180 active fires in northern Ontario, which briefly pushed Toronto’s air quality into the world’s worst category on Wednesday. By nightfall, the plume had traveled hundreds of miles, affecting regions as far west as Minnesota and as far east as New York. Environmental agencies report that millions of Americans will face unhealthy air conditions over the coming week, with particulate‑matter levels exceeding safe thresholds in many affected areas.

Public health officials are advising people to limit outdoor activity, keep windows closed, and use air‑purifying systems if available. As the smoke plume continues to move, state and federal agencies will monitor air‑quality indices closely and issue further guidance as conditions evolve.