Temperatures and humidity are rising in Chicago with a chance for thunderstorms to roll into the region Sunday evening and into Monday.
National Weather Service forecasters say “periods of thunderstorms” are possible Sunday and Monday night, but the exact timing and location are uncertain.
Hot and humid conditions for Chicago are more of a sure thing, according to the weather service, with temperatures hitting 91 and the heat index pushing 105 for Sunday. Monday’s temperatures are expected to be higher at 93, with the potential for a heat index of 110.
The rest of the week will likely be cooler as temperatures drop to the low 80s, according to the weather service.
Six people in Cook County have died for heat-related reasons so far this summer, marking the deadliest stretch of extreme hot-weather deaths in over a decade.
Hot & humidity today & Monday will be accompanied by a threat for storms at times tonight thru Monday evening. It’ll cooler and much less humid Tue-Thu. Dangerous swimming conditions are expected at Lake Michigan beaches Tue & Tue night. pic.twitter.com/WE7l3FTcNU
— NWS Chicago (@NWSChicago) July 26, 2026