August is picking up where July left off, starting out with intense heat and concerns over air quality.
The Illinois EPA issued an air pollution action day Monday for Cook, DuPage, Kane, Kendall, Grundy, Lake, McHenry and Will counties. It's the fourth action day of the year.
On top of air quality concerns, temperatures are expected to get into the low 90s Monday, with heat indexes between 95 and 100, according to NBCChicago's Andy Avalos. Tuesday is expected to be even worse, with temperatures in the mid-90s and heat index values over 100.
Air pollution action days are issued when ozone levels are at or above an unhealthy level for certain groups, including children and adults with pulmonary or respiratory disease, according to the National Weather Service. Members of these groups are advised to stay inside as much as possible.
The warning will be in effect until Monday evening.