Smoke from the Canadian wildfires​ will be visible in the Philadelphia area, but no major impacts on air quality are expected.

The air quality is reaching dangerous levels in parts of the Upper Midwest and north central U.S., where copious amounts of smoke from wildfires in Canada are wafting south across the international border.

Smoke from wildfires burning in three Canadian provinces is spreading into the U.S. Upper Midwest, stirring memories of the severe pollution that drifted south from Canada two years ago during that country's worst fire season on record.