Chicago weather Sunday: Heat, humidity and on-and-off storms
Weather Chicago can expect on Sunday turns warm and humid, with on-and-off showers and thunderstorms as a late-summer heat wave pushes into Chicagoland. Highs reach the mid-to-upper 80s under mostly cloudy skies, morning rain eases by midday, and isolated afternoon storms remain possible before hotter, stormier days early this week.
Key Takeaways
- Sunday begins with showers and storms across the Chicago area, with activity likely fading by noon but isolated afternoon storms possible.
- Highs hit the mid-to-upper 80s with building humidity, signaling the start of a multi-day late-summer heat wave.
- Monday through Wednesday could bring low-to-mid 90s and heat indices approaching 100 degrees.
- An unsettled pattern keeps shower and thunderstorm chances in the forecast through much of the work week.
- Cooler, drier conditions with highs in the low 80s may return by next weekend, according to forecast models.
What Is the Chicago Weather Forecast for Sunday?
The Chicago area got off to a rainy start on Sunday, with showers and thunderstorms tracking across the region in the morning hours. According to the NBC 5 Storm Team, those storms are likely to move out by the noon hour, though a few isolated showers could linger through the afternoon and evening.
FOX 32 Chicago meteorologists expect highs in the upper 80s under mostly cloudy skies, with another round of storm chances returning later in the day. Sunday night brings mostly cloudy conditions with an additional chance for thunderstorms before the heat really builds.
While the rain may be intermittent, forecasters say the bigger story is the warming trend taking hold. Humidity is also climbing, making it feel slightly warmer than the thermometer reading suggests across Chicagoland.
How Hot Will Chicago Get This Week?
After Sunday's mid-to-upper 80s, temperatures keep climbing as September approaches. Monday is forecast to reach the low 90s with a heat index in the mid-90s, according to both NBC 5 Chicago and FOX 32. Most of Monday stays dry, but late-afternoon and evening storms are possible.
Tuesday looks even hotter, with highs in the low to mid 90s and heat indices climbing closer to 100 degrees. Morning showers and thunderstorms are in the forecast for both Tuesday and Wednesday, when mostly sunny skies could push readings into the mid-90s.
Modern forecast models and storm-tracking technology are helping meteorologists map this unsettled late-summer pattern days in advance, giving residents time to prepare for repeated heat and storm risks.
When Will Storms and the Heat Wave Break?
Forecast models suggest the pattern begins breaking down in the back half of the week. Thursday and Friday could see highs in the mid-80s to upper 80s, with continued chances for showers and thunderstorms—particularly Wednesday night into Thursday morning.
By next weekend, rain chances should diminish and temperatures turn more comfortable. NBC 5's extended outlook calls for highs in the low 80s on Saturday and Sunday, a noticeable relief after days of heat-index readings near triple digits.
Residents should stay tuned to local alerts and check authoritative sources like the NBC 5 Chicago Storm Team forecast for real-time updates as this late-summer heat wave unfolds across the region.