The National Weather Service has issued an air quality alert for the suburbs until midnight.
Cook, DuPage, Kane, Lake, McHenry and Will counties are among the areas in the alert.
The alert warns active children and adults, especially those with respiratory problems, to limit time spent outdoors.
Highs today should be in the mid 80s with mostly sunny skies.
The forecast Tuesday calls for highs in the 90s with a chance of storms in the evening.