The Illinois Environmental Protection Agency has determined that an air pollution action day will be declared for the greater Chicago Metropolitan Area and is in effect until midnight CDT Monday night.

An 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 category of the air quality index.

Active children and adults especially people with pulmonary or respiratory disease such as asthma should limit prolonged outdoor activity.