An intense wave of heat and humidity is set to blanket the city of Chicago, bringing sweltering conditions by the weekend, with heat index values likely climbing above 100°F (38°C).
Summer-like Monday with sunshine and comfortable warmth
Monday, June 16 ended on a sunny and warm note across Chicago, with high temperatures reaching the upper 80s°F (around 87°F / 31°C). The night remained mild and muggy, with overnight lows hovering near 70°F (21°C) under partly cloudy skies.
Tuesday: Rising heat with afternoon storms possible
Tuesday, June 17, will begin dry and partly cloudy, with rapidly warming conditions. Temperatures are forecast to soar to around 90°F (32°C) by the afternoon. Scattered showers and thunderstorms are expected to develop late in the day. Some of these may bring gusty winds or hail, though the overall severe threat remains low.
The Storm Prediction Center places northeast Illinois under a Marginal Risk (Level 1 out of 5).
Wednesday: Increased storm risk with cooler temps
Wednesday, June 18, brings on-and-off thunderstorms throughout the day, with slightly cooler highs in the upper 70s to near 80°F (26°C to 27°C). The risk for severe weather increases, and parts of the Chicagoland area are under a Slight Risk (Level 2 out of 5) for strong to severe storms, according to the Storm Prediction Center.
Thursday and Friday: Sunny and pleasant stretch
On Thursday, June 19, and Friday, June 20, conditions turn more stable and pleasant, with sunshine and lower humidity levels. Afternoon highs will settle in the low to mid-80s°F (28°C to 29°C), making for a comfortable lead-up to the weekend.
Weekend outlook: Hot, humid, and dangerously steamy
As we move into the weekend of June 21–22, expect a return to hot and humid weather. Daytime highs will climb into the low to mid-90s°F (34°C), and when factoring in the oppressive humidity, the heat index values could exceed 100°F (38°C), possibly reaching as high as 105°F (41°C) in some areas.
The forecast calls for mostly sunny skies, but the extreme humidity and elevated heat will make it feel uncomfortable and oppressive, especially during the peak afternoon hours across Chicago and the surrounding region.
