More than 830 wildfires burn across Canada, smoke reaches U.S. Northeast

More than 830 wildfires were burning in Canada on Wednesday, along with more than a dozen in northern Minnesota. The fires forced mandatory evacuations and sent smoke into the United States. Smoke from the largest fires in west-central Ontario moved into the upper Midwest and Northeast.

Air quality monitors recorded unhealthy levels in New York City, the Eastern Lake Ontario region, the Central New York region, and parts of Western New York.

Air quality and health guidance New York City Mayor Zohran Mamdani stated that air quality had reached unhealthy levels in parts of the city due to Canadian wildfire smoke. He said poor air quality affects everyone but is especially concerning for people with heart or lung conditions, older adults, pregnant residents, and children.

The mayor urged residents to limit outdoor activities and remain indoors in air-conditioned spaces. The city offered free masks to residents.

Heat and smoke forecast Extreme heat continued across much of the country while smoke spread. Temperatures in parts of the Northeast and upper Midwest were expected to reach the high 90s to triple digits on Wednesday and Thursday. Heavy smoke was reported over Duluth, Minnesota, and Marquette, Michigan, on Wednesday morning.

Extreme smoke covered northern Wisconsin, and areas of heavy smoke moved across New York state and New England, reaching New York City and Boston later in the day. Air quality alerts remained in place from Minnesota to New York City, including all of Wisconsin and Michigan.

Rain is forecast for the upper Midwest on Friday and the Northeast on Saturday, which may help disperse some of the smoke.

Additional weather developments Flash flooding continued in Texas Hill Country after 6 to 16 inches of rain fell earlier in the week. An additional 6 to 12 inches of rain were expected in parts of South-Central Texas, with up to 20 inches possible in some areas.