Canadian Wildfire Smoke Sparks Air Quality Alerts Across 20-Plus U.S. States

On July 16, 2026, smoke from nearly 850 active Canadian wildfires — over 180 in northern Ontario — drifted across the U.S., triggering air quality alerts in more than 20 states from Minnesota to North Carolina. Toronto's air briefly ranked among the world's worst on July 15. Millions face unhealthy PM2.5 — fine particulate matter — as winds push the plume southeast.