Detroit air quality worst in world again as hazardous conditions continue

Charles E. Ramirez, The Detroit News on Jul 17, 2026

By clicking submit, I authorize Arcamax and its affiliates to: (1) use, sell, and share my information for marketing purposes, including cross-context behavioral advertising, as described in our Privacy Policy , (2) add to information that I provide with other information like interests inferred from web page views, or data lawfully obtained from data brokers, such as past purchase or location data, or publicly available data, (3) contact me or enable others to contact me by email or other means with offers for different types of goods and services, and (4) retain my information while I am engaging with marketing messages that I receive and for a reasonable amount of time thereafter. I understand I can opt out at any time through an email that I receive, or by clicking here

DETROIT — Detroit has the most polluted air in the world among major cities on Friday morning as smoke from wildfires in Canada and Minnesota linger, according to Swiss air quality technology company IQAir.

The city had an air quality index, or AQI, of 447 as of 6:45 a.m. Friday, IQAir said. Chicago, Washington D.C., and Toronto, Ontario, Canada, were second, third, and fourth on the company's ranking of the most polluted global major cities.

Detroit had an air quality index, or AQI, of 724 at one point on Thursday, earning it first place for a good part of the day on IQAir's ranking of the most polluted global major cities.

IQAir makes air quality monitoring and air cleaning products. The index is a measure of PM2.5 or particulate matter, and the index reading makes the air "hazardous," according to the company, which means unhealthy for everyone.

AirNow reports the air in most of Michigan is hazardous and it's very unhealthy for the northern tip of the Lower Peninsula and some areas like Flint and Livonia.

AirNow is a partnership of the U.S. Environmental Protection Agency, National Oceanic and Atmospheric Administration, the U.S. National Park Service, NASA, the Centers for Disease Control, and local air quality agencies.

------------