A Beach Hazards Statement was issued early Monday morning, warning people who go to Chicago-area beaches to stay out of Lake Michigan.
Life-threatening waves and currents are expected in the area, according to the National Weather Service.
The alert warns of wave heights of up to 7 feet and strong rip current and structural currents.
Monday is forecast to be a breezy and much cooler day, with temperature highs only reaching into the 70s following a hot and humid weekend.
Along the lakefront, some areas will sit near 70 degrees.
Wind gusts of up to 25 mph are expected.