UPDATE (2:30 p.m. Aug. 20): The EPA has extended Tuesday's poor air quality warning through Wednesday.
Folks with respiratory issues may want to limit their outdoors exposure today.
The EPA has issued their first Chicago-area "action day" alert of the year for Tuesday—warning that high ozone and fine particulate matter levels are likely to be unsafe for "sensitive groups." It lasts until Wednesday.
Residents are also asked to help limit excess pollution today by cutting back on driving and conserving electricity where possible.