Smoke from ongoing wildfires across Canada continued to drift into parts of the United States on Wednesday, causing hazy skies and triggering air quality alerts in multiple states across the upper Midwest and Northeast.

Smoke from Canadian wildfires is causing air quality concerns for millions of Americans in the Midwest and Northeast.

At 4:19 p.m. on Tuesday, the National Weather Service reported an updated air quality alert in effect until Wednesday at midnight for Sussex, Warren, Morris, Hunterdon and Somerset counties.