| NWS Forecast for: Northerly Island to Calumet Harbor IL (LMZ742) Issued by: National Weather Service Chicago, IL Last Update: 358 AM CDT Sat Apr 11 2026 |  |
| Today: East winds around 5 kt increasing to 10 to 15 kt in the late morning. Partly cloudy in the morning, then becoming mostly cloudy. Waves 1 to 2 ft. Tonight: Southeast winds 10 to 15 kt increasing to 15 to 20 kt and becoming south overnight. Chance of showers. Waves 1 to 3 ft building to 2 to 4 ft. Sunday: South winds 15 to 25 kt becoming southwest to 30 kt. scattered showers. A slight chance of thunderstorms in the afternoon. Waves 3 to 5 ft. A small craft advisory will likely be needed. Sunday Night: Southwest winds to 30 kt diminishing to 15 to 25 kt late. Showers and a chance of thunderstorms. Waves 2 to 4 ft. | |
| Zone Forecast: Northerly Island to Calumet Harbor IL (LMZ742) | |
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