Chicago/ Weather & Environment

Lake Michigan Fury: Flood Watch, High Waves Threaten Chicago Sunday

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Published on September 20, 2026
Lake Michigan Fury: Flood Watch, High Waves Threaten Chicago SundaySource: Chris Gallagher / Unsplash

Chicago is waking up to rain, fog and a serious flooding threat Sunday, with thunderstorms capable of dumping heavy rain through midday. One or two areas could receive 3 to 5 inches of rain by the end of Sunday’s event, potentially causing flash flooding. Sunday’s high is expected to be near 68 degrees. Gusty northeast winds will add another layer of misery to an already soggy day.

A Flood Watch remains in effect through 1 p.m. Sunday for Chicago and much of the surrounding region. The National Weather Service Chicago says torrential downpours could trigger flash flooding and urban flooding, with isolated heavier rainfall possible.

Heavy Rain And Strong Winds Dominate Sunday

Showers and thunderstorms are expected to continue through the morning and into the early afternoon, with some storms capable of producing very heavy rain. Northeast winds are expected to become gusty in the 20-to-25-knot range, with some higher gusts possible. Lingering showers are possible into early evening and perhaps overnight.

The latest forecast is a substantial escalation from the weekend outlook described in an earlier Hoodline forecast. A separate river flood watch also covers portions of the Des Plaines River basin, where water levels could rise over the next several days.

Stay Out Of Lake Michigan Through Tuesday

Chicago-area beaches are under a Beach Hazards Statement through Tuesday evening, with high waves and dangerous swimming conditions expected. Officials are urging people to stay out of the water and avoid piers, jetties, breakwalls and other shoreline structures, where conditions can turn deadly quickly.

Cool And Mostly Cloudy Weather Follows

Monday brings another chance of rain showers, a high near 63 degrees and northeast winds. Wednesday and Thursday should be drier, with highs in the 60s through Thursday.

Sunday is a day for avoiding flooded roads, securing loose outdoor items and giving Chicago’s lakefront a wide berth.