Chicago Heat Wave August 20, 2023 7:24 am Chicago Forecast: Heat advisories today with hotter days ahead Temperatures rise to 90° away from the lake today, but dangerous heat builds in the middle of the week Local 2:21 Chicago forecast: Foggy start turns to sunny skies 2:49 Friday morning weather 1:23 Pop-up storms possible ahead of summery warm-up this weekend 2:21 Thursday morning weather 2:07 CHICAGO FORECAST: Warmer temperatures with PM thunderstorms expected Thursday