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Duluth, MN Local Forecast Office

10NM SW Grand Portage MN

Marine Point Forecast

[NOTICE]

Tonight
Low: 55 °F
SW 10kt
1-2ft

Small Craft Advisory
Tuesday
High: 66 °F
WSW 10kt
< 1ft
Tuesday Night
Low: 48 °F
W 10kt
< 1ft
Wednesday
High: 65 °F
SW 10kt
< 1ft
Wednesday Night
Low: 46 °F
Light Wind
< 1ft
Thursday
High: 65 °F
Light Wind
< 1ft
Thursday Night
Low: 54 °F
Light Wind
< 1ft
Friday
High: 67 °F
SW 10kt
< 1ft
Friday Night
Low: 54 °F
NNW 10kt
< 1ft

High and low forecast temperature values represent air temperature.

Water temperature forecast is experimental.

Associated Zone Forecast which includes this point

Last Update: 4:56 pm CDT Aug 17, 2026
Forecast Valid: 6pm CDT Aug 17, 2026-6pm CDT Aug 24, 2026

View Nearby Observations

Detailed Forecast

Tonight

SW wind around 10 kt becoming WNW after midnight. Winds could gust as high as 15 kt. A chance of showers and thunderstorms, mainly before midnight. Waves 1 to 2 ft.

Tuesday

WNW wind around 10 kt becoming WSW in the afternoon. Winds could gust as high as 20 kt. Mostly sunny. Waves 1 ft or less.

Tuesday Night

W wind 5 to 10 kt becoming NW after midnight. Partly cloudy. Waves 1 ft or less.

Wednesday

NW wind 5 to 10 kt becoming SW in the afternoon. Mostly sunny. Waves 1 ft or less.

Wednesday Night

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

Thursday

Variable winds 5 kt or less. A slight chance of showers after 1pm. Waves 1 ft or less.

Thursday Night

Variable winds 5 kt or less. A chance of showers, with thunderstorms also possible after 1am. Waves 1 ft or less.

Friday

NNW wind 5 to 10 kt becoming SW in the afternoon. A chance of showers, mainly after 1pm. Waves 1 ft or less.

Friday Night

WNW wind 5 to 10 kt becoming N after midnight. A slight chance of showers. 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.