The poor air quality continues to prevail in Illinois as Canadian wildfire smoke migrates south into the U.S. As a result, the Illinois Environmental Protection Agency has issued an Air Pollution Action Day for Friday, Aug. 1. Here's what we know.

National Weather Service officials called an air quality alert in effect until midnight as well as a beach hazard warning.

National Weather Service officials issued an air quality alert set to expire at midnight Saturday for the Chicago and surrounding areas. The Illinois Environmental Protection Agency determined an

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.

Smoke from Canadian wildfires has returned to Central Illinois bringing significant reductions in air quality to Central Illinois. Air Quality Alerts have been issued for much of the state through Friday.

An Illinois Air Pollution Action Day is declared when weather conditions are such that widespread ozone and or particulate levels are expected to be at or above the Unhealthy for Sensitive Groups (USG) category of the Air Quality Index for all or almost all of Illinois.

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