Chicago, Ill. – Drivers across northern Illinois should prepare for periods of heavy rain beginning Friday afternoon as repeated downpours increase the risk of localized flooding through Saturday morning. Urban streets, low-lying neighborhoods and poor drainage areas around the Chicago metro could quickly collect water where thunderstorms repeatedly track over the same locations, with localized rainfall totals exceeding 2 inches.
According to the National Weather Service in Chicago, rain will become more widespread Friday afternoon and continue through Saturday night, with the heaviest rainfall expected Friday night into Saturday morning. Thunderstorms are also possible, increasing the potential for brief periods of intense rainfall that could overwhelm drainage systems and cause rapid ponding on roads.
The flooding threat extends across northern Illinois and northwest Indiana, with the greatest concern in heavily developed areas where runoff accumulates quickly. River and creek levels may also rise through the weekend, especially where multiple rounds of rain occur. Motorists should be prepared for reduced visibility during heavier showers and should never drive through flooded roadways.
Along Lake Michigan, strengthening northeast winds will create dangerous swimming conditions beginning late Friday night and continuing through Monday morning. Beachgoers are urged to stay out of the water as life-threatening currents become more likely along Illinois and northwest Indiana beaches.
Cooler-than-normal temperatures will accompany the wet pattern, with highs remaining mainly in the 70s through the weekend before sunshine returns early next week. Drier weather is expected Monday and Tuesday, allowing rivers and streams time to recede, though additional advisories could be issued if rainfall becomes more persistent.
Five-Day Forecast for Chicago, Illinois
- Friday: High 78–84°F, low 64–68°F. Increasing clouds with afternoon showers and thunderstorms. Heavy rain possible overnight.
- Saturday: High 72–75°F, low 62–67°F. Periods of rain and thunderstorms. High swim risk along Lake Michigan.
- Sunday: High 73–78°F, low 57–64°F. Mostly cloudy with lingering showers possible. High swim risk continues.
- Monday: High 77–81°F, low 59–66°F. Partly sunny and drier.
- Tuesday: High 80–84°F, low 64–69°F. Mostly sunny with seasonable temperatures.
