Smoke from wildfires is expected to cause poor air quality and reduced visibility, according to an alert issued by Environment Canada on Thursday.

Smoke from wildfires in Canada has spread more than 5,000 miles, reaching parts of Russia and Europe during the past week.

Smoke from Canadian wildfires carried another day of poor air quality south of the border to the American Midwest. Huge plumes of smoke have even reached Europe, the European Union's climate monitoring service said Tuesday.