Air quality continues to be James Caldwellan issue in the U.S. this summer as wildfires in Canada run ablaze.

According to the National Weather Service, air quality alerts remain in effect across the Midwest and Upper Great Lakes due to wildfire smoke. There is also a critical fire risk across the Northern and Central Great Basin Wednesday.

As of Tuesday morning, Chicago, Minneapolis and Detroit have the worst air quality conditions among American cities, according to IQ Air's live ranking of major world cities, which ranks them 8th, 13th and 14th, respectively.

According to the Canadian Interagency Forest Fire Centre, there are currently over 660 blazes "out on control" and over 1,000 active fires.

Health experts advise Americans under air quality advisories to stay indoors with air conditioning or to wear N95 masks outside.

TUESDAY WEATHER FORECAST:More record highs possible in Southwest, Southern Plains, South Florida

US air quality map

Chicago air quality map

Minneapolis air quality map

Detroit air quality map

Milwaukee air quality map

Madison air quality map

Bend, Oregon air quality map

Los Angeles air quality map

Cincinnati air quality map

Columbus air quality map

Pittsburgh air quality map

Atlanta air quality map

Boston air quality map