Monday is an Air Pollution Action Day, and people with respiratory issues or those sensitive to pollutants in the air should reduce their exposure or heavy exertion outdoors.
Officials from the Illinois Environmental Protection Agency put Monday in the "Code Orange" category.
The day starts off cool with temperatures in the 60s throughout the area but the mercury may climb to close to 90 degrees with increased humidity later in the day. Tuesday will be even warmer, forecast models showed.
A cold front that passes through on Tuesday could cause a few storms to pop in the afternoon and evening hours. Some could be severe. The wind will come from off the lake when that system pushes to the southeast, bringing cooler temperatures and decreased humidity values.