For More Weather Information:

Duluth, MN Local Forecast Office

10NM SW Grand Portage MN

Marine Point Forecast

[NOTICE]

Tuesday
High: 60 °F
NNW 20kt
< 1ft

Small Craft Advisory
Tuesday Night
Low: 49 °F
NW 10kt
< 1ft
Wednesday
High: 66 °F
WSW 10kt
< 1ft
Wednesday Night
Low: 51 °F
W 10kt
< 1ft
Thursday
High: 68 °F
SW 15kt
1-2ft
Thursday Night
Low: 52 °F
WSW 10kt
< 1ft
Friday
High: 69 °F
SW 10kt
< 1ft
Friday Night
Low: 53 °F
SW 10kt
< 1ft
Saturday
High: 70 °F
SW 15kt
2ft

High and low forecast temperature values represent air temperature.

Water temperature forecast is experimental.

Associated Zone Forecast which includes this point

Last Update: 1:21 am CDT Jul 21, 2026
Forecast Valid: 2am CDT Jul 21, 2026-6pm CDT Jul 27, 2026

View Nearby Observations

Detailed Forecast

Tuesday

NNW wind 15 to 20 kt, with gusts as high as 25 kt. Partly sunny. Waves 1 ft or less.

Tuesday Night

NW wind 5 to 10 kt, with gusts as high as 15 kt. Partly cloudy. Waves 1 ft or less.

Wednesday

NW wind 5 to 10 kt becoming WSW in the afternoon. Winds could gust as high as 20 kt. Mostly sunny. Waves 1 ft or less.

Wednesday Night

W wind 5 to 10 kt, with gusts as high as 15 kt. Partly cloudy. Waves 1 ft or less.

Thursday

SW wind 5 to 15 kt. Sunny. Waves 1 to 2 ft.

Thursday Night

WSW wind 5 to 10 kt. A chance of showers and thunderstorms, mainly before 1am. Waves 1 ft or less.

Friday

SW wind around 10 kt, with gusts as high as 20 kt. A slight chance of showers before 1pm. Waves 1 ft or less.

Friday Night

SW wind 5 to 10 kt, with gusts as high as 25 kt. A slight chance of showers, then showers likely and possibly a thunderstorm after 1am. Waves 1 ft or less.

Saturday

SW wind 10 to 15 kt, with gusts as high as 25 kt. A chance of showers, with thunderstorms also possible after 1pm. Waves around 2 ft.

*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.