Chicago, Ill. – A surge of cooler air will bring the chilliest nights of the season so far to northern Illinois, with temperatures dipping into the 40s by late Sunday. The drop comes as a cold front sweeps through the region this weekend, replacing mild summer days with a fall-like chill.
According to the National Weather Service Chicago, overnight lows will slide into the upper 40s to mid-50s Sunday into Monday, especially across outlying suburbs. Daytime highs, which reach the upper 70s Friday and Saturday, will fall back to the low 70s Sunday and only the upper 60s by Monday. Breezy conditions Sunday could make it feel even cooler along the lakefront.
Dense fog is possible late Thursday night into early Friday morning outside of Chicago, creating slick spots for early commuters. A few sprinkles may develop Friday night, with a small chance of showers south of I-57 on Saturday, but widespread rain is unlikely.
Residents should prepare for cooler nights by closing windows and keeping jackets handy, particularly for outdoor evening events. The National Weather Service notes that the cool pattern will likely persist into early next week, with additional advisories possible if stronger fronts develop.
Five Day Forecast for Chicago, Illinois
- Friday: High 79–83, low 62–68; cooler near Lake Michigan, a few sprinkles.
- Saturday: High 76–83, low 52–62; isolated showers southeast of I-57.
- Sunday: High 70–76, low 49–56; partly sunny, breezy.
- Monday: High 66–73, low 46–56; mostly sunny, seasonably cool.
- Tuesday: Highs rebound slightly into the low 70s with continued cool mornings.
