Chicago is set for a hot and humid start to September, with temperatures forecast to climb into the low 90s and the heat index approaching 100F (38C) across much of the area.
The warm spell comes as the city closes out meteorological summer on Monday, August 31, before meteorological autumn begins on Tuesday, September 1. Highs are expected to reach just below 90F (32C) on Monday, with scattered showers or thunderstorms possible at times.
FOX 32 Chicago meteorologist Mike Caplan said the main feature of the forecast was the combination of heat and humidity. Chicago has not recorded a temperature of 90F since July 26.
Chicago heat builds as September begins
Temperatures are forecast to rise into the low 90s on Tuesday and remain at a similar level on Wednesday. Moisture in the air could push heat index values to between 95F and 100F (35C to 38C) across most of the viewing area, with locations south of Interstate 80 potentially feeling a few degrees hotter.
Thunderstorm chances will continue alongside the heat. Far northern Illinois is expected to face the greatest risk on Tuesday and Wednesday, while the National Weather Service has also identified a limited thunderstorm risk around the Chicago area.
Storms temporarily disrupted air travel on Monday, with a ground stop issued at O’Hare International Airport because of thunderstorms until 7am.
Some relief is expected from Thursday, when temperatures should ease back into the mid to upper 80s. However, those levels would still be well above normal for early September.
Rainfall prospects are expected to remain scattered towards the weekend, with longer dry periods likely to dominate. The forecast is expected to stay warmer than usual even as the first days of meteorological autumn get under way.
