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Duluth, MN Local Forecast Office

10NM SW Grand Portage MN

Marine Point Forecast

[NOTICE]

Tonight
Low: 59 °F
Light Wind
1ft
Sunday
High: 69 °F
WNW 10kt
< 1ft
Sunday Night
Low: 53 °F
Light Wind
< 1ft
Monday
High: 69 °F
SW 15kt
1-2ft
Monday Night
Low: 54 °F
SW 10kt
< 1ft
Tuesday
High: 66 °F
WNW 10kt
< 1ft
Tuesday Night
Low: 50 °F
Light Wind
< 1ft
Wednesday
High: 64 °F
WSW 10kt
< 1ft
Wednesday Night
Low: 50 °F
Light Wind
< 1ft

High and low forecast temperature values represent air temperature.

Water temperature forecast is experimental.

Associated Zone Forecast which includes this point

Last Update: 9:01 pm CDT Aug 15, 2026
Forecast Valid: 10pm CDT Aug 15, 2026-6pm CDT Aug 22, 2026

View Nearby Observations

Detailed Forecast

Tonight

Variable winds 5 kt or less. Showers and thunderstorms likely before 3am, then a slight chance of showers between 3am and 4am. Patchy fog between 1am and 2am. Waves around 1 ft.

Sunday

W wind 5 to 10 kt becoming NW in the morning. Winds could gust as high as 15 kt. Partly sunny. Waves 1 ft or less.

Sunday Night

Variable winds 5 kt or less. Partly cloudy. Waves 1 ft or less.

Monday

WNW wind 5 to 15 kt becoming SW in the afternoon. Mostly sunny. Waves 1 to 2 ft.

Monday Night

SW wind 5 to 10 kt becoming W after midnight. Winds could gust as high as 15 kt. A chance of showers before 1am. Waves 1 ft or less.

Tuesday

WNW wind 5 to 10 kt. Partly sunny. Waves 1 ft or less.

Tuesday Night

Variable winds 5 kt or less. Mostly cloudy. Waves 1 ft or less.

Wednesday

NNW wind 5 to 10 kt becoming WSW in the afternoon. A slight chance of showers. Waves 1 ft or less.

Wednesday Night

Variable winds 5 kt or less. Partly cloudy. Waves 1 ft or less.

*Notices:

This forecast is for a single location. For safety concerns, mariners should be aware of the weather over a larger area. Forecast information for a larger area can be found within the zone forecast and the NDFD graphics.
The forecast conditions at a particular point may not exceed the criteria of a Small Craft Advisory, Gale, Storm etc. These watches/warnings/advisories are issued for the entire zone in which the point resides and mariners should act accordingly.