Measurements:
°C
°F
Duluth
-6°F
SE 4 mph
Feels like: -20°F
Precip: 0%
World Resorts USA Duluth Weather

Duluth Sea Water Temperature

Current Sea Water Temperature:
+31.2°F
Maximum Sea Water Temperature in January: 36.6°F
Minimum Sea Water Temperature in January: 29.8°F
Average water temperature in January: 32.0°F

Sea Water Temperature for the Last 10 Days:

January 29 31.2°F January 24 31.8°F
January 28 31.4°F January 23 31.6°F
January 27 31.4°F January 22 31.6°F
January 26 31.6°F January 21 32.0°F
January 25 31.6°F January 20 32.4°F

When is the Warmest Sea for Duluth?

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

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 Duluth was 69.4°F. The maximum and minimum values were 64.0°F and 73.4°F respectively.

Sea Water Temperature in July

Select Year: 2025 2024 2023

The average sea surface temperature in July 2025 for Duluth was 64.9°F. The maximum and minimum values were 59.0°F and 73.6°F respectively.

Sea Water Temperature in September

Select Year: 2025 2024 2023

The average sea surface temperature in September 2025 for Duluth was 61.9°F. The maximum and minimum values were 59.2°F and 66.8°F respectively.

Best Time to Visit Duluth
The most sunny months:
September 14 days
August 13 days
July 12 days
The most warm months:
July 77.4 °F
August 76.5 °F
June 70.6 °F
Warmest sea temperature:
August 67.6 °F
July 65.4 °F
September 63.7 °F
The most cold months:
January 14.4 °F
February 15.5 °F
December 21.4 °F
The most rainy months:
June 3 days
August 3 days
July 3 days
The most windy months:
April 9 mph
March 8 mph
November 8 mph

Duluth on the Weather Map

USA Resorts:
NAME
Chicago 0
Hawaii +74
Honolulu +74
Houston +38
Las Vegas +48
Los Angeles +56
Maui +68
Miami +64
Miami Beach +70
New York +12
San Diego +60
San Francisco +50
Sarasota +58
Tampa +58
Washington +12
24 Hours Weather Forecast
Duluth
Local time: 09:52
29 jan, thursday
1200 -2°F
S
4 mph
1500 4°F
SW
4 mph
1800 2°F
S
2 mph
2100 -2°F
S
8 mph
30 jan, friday
0000 -4°F
S
7 mph
0300 -8°F
S
8 mph
0600 -12°F
S
6 mph
0900 -12°F
S
7 mph