National Weather Service Marine Forecast FZUS53 KLOT

FZUS53 KLOT 210225
NSHLOT

Nearshore Marine Forecast
National Weather Service Chicago/Romeoville IL
925 PM CDT Thu Aug 20 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>742-210915
Winthrop Harbor to Wilmette Harbor IL
Wilmette Harbor to Northerly Island IL
Northerly Island to Calumet Harbor IL
925 PM CDT Thu Aug 20 2026

REST OF TONIGHT
Northeast winds around 10 kt becoming southwest after midnight. Increasing cloudiness. Waves 1 to 2 ft subsiding to 1 ft or less.

FRIDAY
Southwest winds 10 to 15 kt becoming south in the afternoon. Slight chance of showers and thunderstorms in the afternoon. Waves 1 to 2 ft.

FRIDAY NIGHT
Southwest winds around 10 kt becoming west overnight. Chance of showers and thunderstorms, mainly in the evening. Waves 1 to 2 ft.

SATURDAY
Northwest winds 10 to 20 kt becoming north. Mostly cloudy in the morning then clearing. Waves 1 to 3 ft.

LMZ743>745-210915
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN
Burns Harbor to Michigan City IN
925 PM CDT Thu Aug 20 2026

REST OF TONIGHT
Northeast winds around 10 kt becoming south after midnight. Increasing cloudiness. Waves 1 to 2 ft.

FRIDAY
South winds around 10 kt. Partly cloudy in the morning, then becoming mostly cloudy. Waves around 1 ft.

FRIDAY NIGHT
South winds 10 to 15 kt becoming southwest. Chance of showers and thunderstorms. Waves 1 to 2 ft.

SATURDAY
Northwest winds 10 to 20 kt becoming north 15 to 25 kt in the afternoon. Mostly cloudy in the morning then clearing. Waves 2 to 4 ft building to 3 to 5 ft.

DK