Heat advisory issued for Chicago, surrounding counties until Wednesday

A Heat Advisory has been issued for Chicago and a number of surrounding Illinois counties from Monday afternoon through Wednesday night.

The advisory has been issued for Cook, Will, Grundy, LaSalle, Kankakee and Kendall counties and Benton, Jasper, Lake, Newton and Porter counties in Indiana from 12 p.m. to 9 p.m. Tuesday and Wednesday.

The National Weather Service issues heat advisories when there are dangerous heat conditions that aren't expected to reach the criteria for a heat watch or warning. When a heat advisory is in effect you should consider postponing or rescheduling outdoor activities, especially during the hottest parts of the day, and drink plenty of water and take frequent shade breaks.

Heat and humidity will build through Wednesday, with heat index values of 95 to 100 degrees possible, especially of I-80. Currently, Wednesday is forecast to be the hottest day of the week, with the heat index making it feel like 100 to 105 degrees.

Then, starting Thursday, rain will help break the heat as we head into the weekend.