Billowing smoke from Canadian wildfires wafts into the U.S.

Clouds of wildfire smoke like this one in Flin Flon, Manitoba, are wafting into the Northern Plains and Midwest.

The Manitoba wildfires have forced 17,000 people to flee the province. Plumes of heavy smoke are expected to drift into the United States over Friday and Saturday, affecting millions of Americans.

(Image credit: Government of Manitoba)