Wildfire Smoke Air Quality Alert: Detroit among top 10 most polluted cities in the world

  • 3 min read
  • by IQAir Staff Writers
Smoke over a lake

Is the air quality good in Detroit?

As of August 4, 2025, Detroit, Michigan is among the most polluted major city in the world. Wildfire smoke from fires in northern Canada drifted across the Midwest and New England, bringing regional air quality into the "unhealthy for sensitive" and groups," "unhealthy," ranges for Detroit and multiple cities.

For a more detailed look, see Detroit’s air quality map.

Detroit was the 3rd most polluted city on Friday morning. Toronto, Ontario was listed as the 7th most polluted city in the world, while Montreal, Quebec was ranked 11th.

Ranked list

Detroit was listed as one of the most polluted major cities on the evening of August 4. Source: IQAir.

Why is there an air quality alert in Detroit?

There are numerous wildfires burning across northern Canada, particularly in Saskatchewan, Manitoba, and Ontario. For a closer look at wildfires in Canada, see the AirVisual air quality map.

Forecast

Hourly air quality forecast for Detroit, Michigan on August 4. Source: IQAir.

Air quality is forecasted to improve in the city on Tuesday.

Which cities are being affected by wildfire smoke?

Several cities in Michigan, Minnesota, New England, Ohio, New York, Pennsylvania, and Wisconsin are experiencing poor air quality, including:

Cities across Canada are also being impacted by poor air quality from wildfire smoke, including:

Air quality map

Air quality map of the Great Lakes region on August 1. Source: IQAir.

Are there any alerts in place?

There is an air quality alert for Connecticut, Delaware, northern Indiana, Maine, Massachusetts, Michigan, Minnesota, New Hampshire, New York, Rhode Island, Vermont and Wisconsin as well as parts of Minnesota, New Jersey, and Pennsylvania according to the U.S. National Weather Service (1).

How can I protect myself from poor air quality?

About IQAir

IQAir is a Swiss technology company that empowers individuals, organizations and governments to improve air quality through information and collaboration.

Article resources

[1] U.S. National Weather Service. (2025, August 4). Home page.

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