Wildfires in Canada are pushing smoke south and into the United States, impacting many major cities. According to the World Air Quality Index, Detroit, Chicago and Minneapolis are all in the top five cities with the worst air quality in the world Wednesday.

What Happened: Detroit is listed at No. 2, right behind Dubai, while Chicago and Minneapolis are in third and fourth place, respectively.

Washington, D.C. is also in the top 10, taking the ninth spot. The air in Detroit has a visible haze or smoky tint.

Experts warn that people with underlying conditions, like asthma or heart problems, should avoid spending too much time outside if possible. 

The fires are burning in the Quebec and Ontario regions of Canada. Some Canadian officials worry this could be the worst year ever for forest fires for the country. 

Detroit’s air quality has a rating of 232 Wednesday on the IQAir rating system, which puts Detroit’s air in the "very unhealthy" category. If the air quality rating in the Motor City continues to worsen and crosses 300, it would be in the "hazardous" category. 

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