| NWS Forecast for: Northerly Island to Calumet Harbor IL (LMZ742) Issued by: National Weather Service Chicago, IL Last Update: 919 PM CDT Fri Jul 31 2026 | |
Rest Of Tonight: Southeast winds 15 to 20 kt becoming east 20 to 25 kt. Showers and slight chance of thunderstorms late in the evening, then showers and a chance of thunderstorms after midnight. Waves 1 to 3 ft building to 4 to 7 ft occasionally to 9 ft. Saturday: East winds to 30 kt becoming northeast in the afternoon. Showers and a chance of thunderstorms. Waves 5 to 8 ft occasionally to 10 ft building to 7 to 10 ft occasionally to 13 ft. Saturday Night: Northeast winds to 30 kt becoming north. Showers likely and slight chance of thunderstorms in the evening, then chance of showers overnight. Waves 7 to 10 ft occasionally to 13 ft subsiding to 6 to 9 ft occasionally to 12 ft. Sunday: North winds 20 to 25 kt increasing to 30 kt. Slight chance of showers in the morning. Waves 6 to 9 ft occasionally to 12 ft. | |
| Zone Forecast: Northerly Island to Calumet Harbor IL (LMZ742) | |
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