Canadian Wildfire Smoke Triggers Air-Quality Alerts in 14 U.S. States

Smoke from Canadian wildfires produced unhealthy air-quality readings in parts of the upper Midwest and Northeast on Wednesday, prompting alerts across 14 states. More than 830 wildfires burned across Canada that day, with the largest fires in west-central Ontario sending plumes southward. Mandatory evacuations occurred in affected Canadian areas.

More than a dozen fires also burned in northern Minnesota. Air quality monitors recorded unhealthy readings in New York City, the Eastern Lake Ontario region, Central New York, and parts of Western New York. Heavy smoke covered Duluth, Minnesota, Marquette, Michigan, and northern Wisconsin in the morning.

Additional plumes crossed New York state and New England, reaching New York City and Boston later in the day. The mayor said poor air quality affects everyone but is especially concerning for people with heart or lung conditions, older adults, pregnant residents, and children.

He urged residents to limit outdoor activities and remain indoors in air-conditioned spaces, and the city offered free masks.

Air quality alerts remained in place from Minnesota to New York City, including all of Wisconsin and Michigan. Temperatures in parts of the Northeast and upper Midwest were forecast to reach the high 90s to triple digits on Wednesday and Thursday. An extreme heat warning was issued for the Los Angeles area on Wednesday and is expected to remain in effect until Thursday night.