Coastal Waters Forecast for Northerly Island to Calumet Harbor IL (LMZ742) (Text-Only)
NWS Forecast for: Northerly Island to Calumet Harbor IL (LMZ742)
Issued by: National Weather Service Chicago, IL
Last Update: 340 AM CST Wed Dec 31 2025




Today: Northwest winds 10 to 20 kt increasing to 20 to 25 kt. snow in the afternoon. Waves 2 to 4 ft building to 3 to 5 ft.

Tonight: Northwest winds 20 to 25 kt diminishing to 15 to 20 kt. Slight chance of snow in the evening. Waves 4 to 7 ft occasionally to 9 ft subsiding to 3 to 6 ft occasionally to 8 ft.

Thursday: Northwest winds 10 to 15 kt becoming west. Partly cloudy in the morning, then becoming mostly cloudy. Waves 3 to 5 ft subsiding to 1 to 3 ft.

Thursday Night: West winds 10 to 15 kt. Mostly cloudy. Waves 1 to 2 ft.







Zone Forecast: Northerly Island to Calumet Harbor IL (LMZ742)

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