Chicago, IL – Northern Illinois residents are in for a stretch of summerlike warmth through midweek, with temperatures climbing into the upper 80s and even near 90 degrees in some areas before showers and storms arrive on Thursday, according to the National Weather Service (NWS) Chicago.
Warm, Dry Start to the Week
From Monday through Wednesday, forecasters expect partly sunny skies and dry conditions across the region. High temperatures will range from 82 to 90 degrees inland, while communities along the Lake Michigan shoreline will stay cooler thanks to persistent lake breezes. Lakeside highs are forecast to hover in the 70s to low 80s, providing a sharp contrast to the hotter conditions further inland.
Overnight lows will remain mild, with readings dipping into the mid-50s away from the city and holding in the mid-60s closer to downtown. The warmest period is likely on Tuesday and Wednesday, when inland locations could push to near 90 degrees, a level rarely seen in mid-September.
Thursday Brings Change
The first notable weather shift is expected on Thursday. Skies will be partly sunny with highs in the low to mid-80s, but increasing humidity and an approaching disturbance will bring a 30% chance of showers and thunderstorms. While forecasters do not anticipate severe weather at this time, late-summer storms can still bring heavy downpours, lightning, and gusty winds that could briefly impact outdoor activities and commutes.
Above-Average Mid-September
This week’s pattern highlights just how unseasonably warm the month has been so far for Chicago and much of Illinois. Normal mid-September highs for the city typically run in the low to mid-70s, meaning temperatures through Wednesday will be running 10 to 15 degrees above average.
Meteorologists note that while the warmth may be welcome for many, residents should remain aware of changing weather conditions later in the week. Even if Thursday’s storms remain scattered, they could bring quick bursts of rain before cooler air filters into the region.
For now, the NWS encourages residents to enjoy the stretch of sunshine and warmth while keeping an eye on updated forecasts. The upcoming week offers one last taste of summer before autumn weather patterns begin to take firmer hold.
