On Friday more than 100 million Americans were under air quality alerts as smoke from hundreds of Canadian wildfires drifted across the Midwest toward the East Coast.
The air quality alerts extended from Wisconsin and northern Illinois through Michigan and Ohio and eastward.
On Friday morning, ranking site IQ Air listed three U.S. cities among the top six major cities in the world with the worst air quality: Detroit, Washington DC and New York City, though Toronto and Montreal in Canada ranked as the very worst.
Some 500 active wildfires are currently raging across Canada—its worst fire season on record.
An area spanning nearly 20 million acres—bigger than West Virginia—has already burned. About half the fires were considered out of control as of Wednesday, spreading from the Pacific to the Atlantic coasts.
The EPA on Friday was advising Americans to check air quality updates at airnow.gov or use the @AIRNow app , as smoke levels “can change rapidly during the day.”
Storms on Thursday brought some relief from the smoke in parts of the Midwest, and more rain there Friday would hopefully help further. But smoke was expected to dissipate less quickly in the Ohio Valley and the Mid-Atlantic, where storms on Friday were forecast to be more isolated.
