Measurements:
°C
°F
Grand Marais
14°F
E 9 mph
Feels like: 0°F
Precip: 0%
World Resorts USA Grand Marais Weather

Grand Marais Sea Water Temperature

Current Sea Water Temperature:
+37.8°F
Maximum Sea Water Temperature in December: 43.2°F
Minimum Sea Water Temperature in December: 36.2°F
Average water temperature in December: 38.5°F

Sea Water Temperature for the Last 10 Days:

December 05 37.8°F November 30 39.4°F
December 04 38.4°F November 29 39.0°F
December 03 39.2°F November 28 39.4°F
December 02 39.0°F November 27 39.6°F
December 01 39.2°F November 26 39.6°F

When is the Warmest Sea for Grand Marais?

According to our data for the last three years for Grand Marais the highest average sea water temperature was in August, September and October.

Average Water Temperature by Month, °F

Sea Water Temperature in August

Select Year: 2025 2024 2023

The average sea surface temperature in August 2025 for Grand Marais was 62.5°F. The maximum and minimum values were 56.6°F and 67.4°F respectively.

Sea Water Temperature in September

Select Year: 2025 2024 2023

The average sea surface temperature in September 2025 for Grand Marais was 59.5°F. The maximum and minimum values were 55.6°F and 64.2°F respectively.

Sea Water Temperature in October

Select Year: 2025 2024 2023

The average sea surface temperature in October 2025 for Grand Marais was 54.2°F. The maximum and minimum values were 49.6°F and 61.4°F respectively.

Best Time to Visit Grand Marais
The most sunny months:
September 14 days
August 13 days
July 12 days
The most warm months:
August 70.1 °F
July 69.0 °F
September 63.5 °F
Warmest sea temperature:
August 61.3 °F
September 60.2 °F
October 53.1 °F
The most cold months:
February 15.4 °F
January 16.0 °F
December 23.2 °F
The most rainy months:
August 3 days
April 2 days
July 2 days
The most windy months:
November 10 mph
December 9 mph
April 9 mph

Grand Marais on the Weather Map

USA Resorts:
NAME
Chicago -2
Hawaii +78
Honolulu +78
Houston +44
Las Vegas +40
Los Angeles +52
Maui +72
Miami +72
Miami Beach +80
New York +18
San Diego +54
San Francisco +46
Sarasota +62
Tampa +62
Washington +28
24 Hours Weather Forecast
Grand Marais
Local time: 02:31
05 dec, friday
0300 14°F
E
9 mph
0600 16°F
E
6 mph
0900 10°F
SE
5 mph
1200 18°F
NE
7 mph
1500 20°F
NE
9 mph
1800 18°F
E
10 mph
2100 14°F
SE
14 mph
06 dec, saturday
0000 14°F
SE
11 mph