Coastal Waters Forecast for Winthrop Harbor to Wilmette Harbor IL (LMZ740) (Text-Only)
NWS Forecast for: Winthrop Harbor to Wilmette Harbor IL (LMZ740)
Issued by: National Weather Service Chicago, IL
Last Update: 941 AM CDT Tue May 12 2026




Rest Of Today: South winds 15 to 25 kt becoming southwest to 30 kt with a few gale force gusts to 35 kt. Scattered showers and thunderstorms this afternoon and evening. Waves 3 to 5 ft.

Tonight: Southwest winds to 30 kt becoming northwest 20 to 25 kt late. Scattered showers and slight chance of thunderstorms in the evening. Waves 2 to 4 ft subsiding to 1 to 3 ft.

Wednesday: Northwest winds 20 to 25 kt becoming north in the afternoon. Partly cloudy in the morning, then becoming mostly cloudy. Waves 2 to 4 ft.

Wednesday Night: North winds 10 to 20 kt becoming northwest and diminishing to around 10 kt. Mostly clear. Waves 1 to 3 ft.







Zone Forecast: Winthrop Harbor to Wilmette Harbor IL (LMZ740)

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