Overview

• An Extreme Heat Warning covers Cook County from 10 a.m. Saturday through Tuesday evening as heat index values soar above 100°.
• A Heat Advisory extends through Tuesday for surrounding counties under the high-pressure system fueling the heat wave.
• Chicago’s Office of Emergency Management and Communications will host a 9:30 a.m. Friday press briefing to outline safety guidelines and cooling options.
• Showers and weakening thunderstorms arriving Friday will temporarily drop afternoon highs into the low 80s before the sun returns.
• A more widespread round of rain is expected Tuesday afternoon, offering relief and leading to a stormy pattern with highs in the upper 80s to low 90s through Thursday.