National Weather Service Marine Forecast FZUS53 KLOT

FZUS53 KLOT 310200
NSHLOT

Nearshore Marine Forecast
National Weather Service Chicago/Romeoville IL
900 PM CDT Thu Jul 30 2026

For waters within five nautical miles of shore on Lake Michigan

Waves are provided as a range of significant wave heights, which is the average of the highest 1/3 of the waves, along with the average height of the highest 10 percent of the waves which will occasionally be encountered.

LMZ740>742-310915
Winthrop Harbor to Wilmette Harbor IL
Wilmette Harbor to Northerly Island IL
Northerly Island to Calumet Harbor IL
900 PM CDT Thu Jul 30 2026

REST OF TONIGHT
South winds around 5 kt. Mostly cloudy. Waves 1 ft or less.

FRIDAY
South winds 10 to 15 kt becoming southeast in the afternoon. Chance of showers in the afternoon. Waves 1 ft or less building to 1 to 2 ft.

FRIDAY NIGHT
Southeast winds 15 to 20 kt becoming east and increasing to 20 to 25 kt. Showers and slight chance of thunderstorms in the evening, then showers and a chance of thunderstorms overnight. Waves 1 to 3 ft building to 4 to 6 ft occasionally to 8 ft. A small craft advisory will likely be needed.

SATURDAY
East winds 20 to 25 kt becoming northeast in the afternoon. Showers and a chance of thunderstorms in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Waves 4 to 7 ft occasionally to 9 ft.

LMZ743>745-310915
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN
Burns Harbor to Michigan City IN
900 PM CDT Thu Jul 30 2026

REST OF TONIGHT
South winds around 5 kt. Mostly cloudy early, then becoming partly cloudy. Waves 1 ft or less.

FRIDAY
South winds 10 to 15 kt becoming southeast in the afternoon. Chance of showers in the afternoon. Waves 1 ft or less.

FRIDAY NIGHT
Southeast winds 10 to 20 kt. Showers likely in the evening, then showers and a chance of thunderstorms overnight. Waves 1 to 3 ft.

SATURDAY
East winds 15 to 20 kt becoming northeast and increasing to 20 to 25 kt in the afternoon. Showers and a chance of thunderstorms. Waves 2 to 4 ft building to 4 to 6 ft occasionally to 8 ft. A small craft advisory will likely be needed.

Ratzer