National Weather Service United States Department of Commerce

The heat will continue on Saturday after a very warm night tonight. Again, ensure you demonstrate heat preparedness and safety. Some showers and storms are possible Saturday afternoon, mainly north of I-80, with chances increasing area wide through Saturday night into Sunday morning.
The heat will continue on Saturday after a very warm night tonight. Again, ensure you demonstrate heat preparedness and safety, and encourage your friends and family. Some showers and storms are possible Saturday afternoon, mainly north of I-80, with chances increasing area wide through Saturday night into Sunday morning.
As a cold front approaches Saturday afternoon through Saturday evening, thunderstorms are expected to develop and gradually increase in coverage from north to south. Strong to severe thunderstorms with a wind risk are possible. Torrential rainfall will be likely with all thunderstorms, which could cause localized flash flooding. Also, frequent cloud to ground lightning will be likely with all thunderstorms. Check the latest forecast updates, stay weather ready and aware Saturday PM, and have a plan to quickly access shelter if you will be outdoors.
Chance for thunderstorms south of Interstate 80 Sunday. A period of quiet and dry conditions are expected for Monday through Wednesday.
For more, see weather.gov/chicago/heatprepare and weather.gov/heat