Chicago, Illinois – Heat and humidity will surge back into northern Illinois on Sunday, bringing steamy conditions and a renewed chance for afternoon and evening thunderstorms.
According to the National Weather Service in Chicago, high temperatures will soar into the low 90s, with peak heat indices topping 100 degrees in the city and surrounding suburbs. The hottest conditions are expected along and south of I-80, including Joliet, Kankakee, and portions of the I-57 corridor. Scattered thunderstorms may develop later in the day, especially after 3 p.m., with potential for gusty winds and brief downpours.
Sunday’s heat will follow a brief break Friday and Saturday when highs stay in the 80s. With overnight lows sticking near 70 degrees, the risk of heat-related illness rises—residents should stay cool, drink water, and check on neighbors. Outdoor plans, especially in Cook, Will, and DuPage counties, could be interrupted by fast-moving storms.
Conditions will ease slightly Monday, but daily storm chances linger into next week.
More advisories are possible Sunday morning as heat and storm details become clearer.
