Current sea water temperature:
+38.3°F
| Minimum sea water temperature in December: | 43.9°F |
| Maximum sea water temperature in December: | 37.0°F |
| Average sea water temperature in December: | 39.5°F |
| more information | |
14 days
forecast
forecast
| Grand Marais |
monthly
weather
weather
| Grand Marais |
Sea water temperature for the last 10 days:
| December 24 | 38.3°F | December 19 | 38.7°F |
| December 23 | 37.0°F | December 18 | 38.7°F |
| December 22 | 37.9°F | December 17 | 39.2°F |
| December 21 | 39.2°F | December 16 | 38.1°F |
| December 20 | 37.8°F | December 15 | 37.8°F |
Monthly sea water temperature, °F
When is the warmest sea in Grand Marais?
Based on the data about daily sea water temperature for the last three years the warmest sea in Grand Marais was noticed in August, September and October.
Monthly Sea Temperatures in Grand Marais, °F
Sea water temperature in August, °F
Show year:
2025
2024
2023
The average sea water temperature in August of 2025 was 61.3°F. The highest and lowest sea temperatures during the month were 65.7°F and 55.9°F.
Sea water temperature in September, °F
Show year:
2025
2024
2023
The average sea water temperature in September of 2025 was 58.5°F. The highest and lowest sea temperatures during the month were 62.8°F and 55.0°F.
Sea water temperature in October, °F
Show year:
2025
2024
2023
The average sea water temperature in October of 2025 was 53.8°F. The highest and lowest sea temperatures during the month were 60.3°F and 49.6°F.
current
weather
weather
| Grand Marais |
weather in
December
December
| Grand Marais |
Best time for vacation in Grand Marais
Grand Marais on a weather map
Places in USA:
Name
°F
24 Hours Forecast
Grand Marais
Local time: 07:37
December 24, wednesday
0900

28°F
NW
2 mph
2 mph
1200

32°F
N
4 mph
4 mph
1500

34°F
NE
5 mph
5 mph
1800

30°F
SE
4 mph
4 mph
2100

28°F
S
7 mph
7 mph
December 25, thursday
0000

21°F
S
7 mph
7 mph
0300

18°F
S
7 mph
7 mph
0600

16°F
SW
6 mph
6 mph



























