Smoke from deadly Canadian wildfires covers large swath of US prompting widespread air quality alerts
As wildfire smoke spreads across the country, air quality alerts have been posted for the Upper Midwest and Northeast, including Philadelphia and New York City.
Canadian Wildfire smoke brings air quality alerts, hazy skies to Midwest and Northeast
Air quality alerts have been posted for the Upper Midwest and the Interstate 95 corridor between Philadelphia and Connecticut due to smoke from wildfires raging in Canada.
MINNEAPOLIS – Deadly wildfires in Canada continue to spread and affect the air quality of bordering U.S. states.
With the wildfires not expected to slow down, a continued drop in air quality is possible for some U.S. cities, especially in the Upper Midwest.
Air quality alerts cover all of Wisconsin, Iowa and most of Minnesota and Michigan's Upper Peninsula through at least Thursday morning.
Air quality alerts have also been posted for the Interstate 95 corridor in the Northeast between Philadelphia, New York City and Connecticut. These are due to ground-level ozone mixing with some wildfire smoke at times.
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Canadian wildfire smoke chokes Minneapolis
A plume of heavy wildfire smoke was very visible Tuesday at Bryant Lake Park in Minneapolis (Video Credit: KMSP).
Heavy smoke moved into Minneapolis on Tuesday and was visible throughout most of the day.
According to IQAir.com, Minneapolis was ranked fourth in the world Wednesday for cities with the worst air quality. The Minnesota Pollution Control Agency advised people with lung disease, asthma, heart conditions and other health concerns to limit their time outdoors.
This graphic shows air quality alerts posted in the Upper Midwest through Thursday morning.
(FOX Weather)
In addition to poor air quality and hazy skies, another noticeable effect is vibrant orange-colored sunrises and sunsets as light is filtered by the smoke particles.
A red sunrise was observed over New York City on Wednesday morning.
Red sunrise amid wildfire smoke in New York City
With the wildfires not expected to slow down, a continued drop in air quality is possible for some U.S. cities, especially in the Upper Midwest, while thicker smoke has arrived in the Northeast.
Marquette, Michigan, had an air quality index (AQI) rating of 817 on Tuesday afternoon, while the town of Hancock, Michigan, peaked over 800 late Tuesday morning.
Smoke was still an issue across Michigan's Upper Peninsula Wednesday, with the web camera from the Mackinac Bridge showing much of the bridge obscured.
![Smoke obscures Michigan's Mackinac Bridge]()
Image 1 of 4Smoke obscures Michigan's Mackinac Bridge on June 4, 2025. (Mackinac Bridge Authority)
![Smoke obscures Michigan's Mackinac Bridge]()
Image 2 of 4Smoke obscures Michigan's Mackinac Bridge on June 4, 2025. (Mackinac Bridge Authority)
![Smoke obscures Michigan's Mackinac Bridge]()
Image 3 of 4Smoke obscures Michigan's Mackinac Bridge on June 4, 2025. (Mackinac Bridge Authority)
![Smoke obscures Michigan's Mackinac Bridge]()
Image 4 of 4Smoke obscures Michigan's Mackinac Bridge on June 4, 2025. (Mackinac Bridge Authority)
Communities south of the U.S.-Canada border reported AQI ratings between 200 and 400, which are considered to be unhealthy or even hazardous.
A value between 0 and 50 on the AQI scale is considered "good," while anything over 301 reaches dangerous levels.
Smoky sky in Wisconsin from Canadian wildfires
Uncontrolled wildfires in Canada continue to waft smoke into the central and eastern U.S. This smoky scene was captured near Sheboygan, Wisconsin, on Sunday. Air quality alerts are in effect to the west in Minnesota.
A couple in Manitoba were killed May 13 when a fire swept through the area of Lac du Bonnet.