Chicago Nearshore Marine Forecasts by Zone

 
 

 
 
 
 
 
FORECAST For Wilmette Harbor to Northerly Island (LMZ741)
 
 
 
 
 LMZ740>742-100315-
 Winthrop Harbor to Wilmette Harbor IL-
 Wilmette Harbor to Northerly Island IL-
 Northerly Island to Calumet Harbor IL-
 244 PM CDT Mon Mar 9 2026
 

 TONIGHT
 Southwest winds 10 to 20 kt diminishing to 10 to 15 kt
 early, then becoming north toward morning. Patchy fog after
 midnight. Waves 1 to 3 ft.

 TUESDAY
 North winds 10 to 20 kt. Patchy fog. Chance of drizzle
 and showers in the afternoon. Waves 2 to 4 ft building to 3 to 5
 ft.

 TUESDAY NIGHT
 North winds 15 to 20 kt. Patchy fog. Rain
 showers with thunderstorms likely in the evening, then showers
 and a chance of thunderstorms overnight. Waves 4 to 6 ft
 occasionally to 8 ft. A small craft advisory will likely be
 needed.

 WEDNESDAY
 North winds 20 to 25 kt becoming northwest to 30 kt.
 Patchy fog in the morning. Rain showers in the morning, then
 chance of rain and snow showers in the afternoon. Waves 4 to 7 ft
 occasionally to 9 ft building to 5 to 8 ft occasionally to 10 ft.
 A small craft advisory will likely be needed.
 
 $$