Chicago air quality remains in the top five worst in the world Friday with an Air Quality Alert in place from Canadian wildfire smoke.

Smoke from wildfires blazing across Canada is once again wafting over huge portions of the U.S. Midwest and worsening air quality there. On August 1 conditions are particularly bad in Minnesota, Iowa and Illinois.

Wildfire smoke from Canada is blanketing the skies in the Midwest, leaving millions with dangerous breathing conditions.