Measurements:
°C
°F
Duluth
16°F
NE 9 mph
Feels like: 2°F
Precip: 100%
World Resorts USA Duluth Weather

Duluth Sea Water Temperature

Current Sea Water Temperature:
+40.0°F
Maximum Sea Water Temperature in December: 42.0°F
Minimum Sea Water Temperature in December: 30.0°F
Average water temperature in December: 35.6°F

Sea Water Temperature for the Last 10 Days:

December 05 40.0°F November 30 41.4°F
December 04 40.0°F November 29 41.8°F
December 03 41.4°F November 28 42.2°F
December 02 41.4°F November 27 42.0°F
December 01 41.4°F November 26 42.4°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 15.0 °F
February 15.5 °F
December 22.5 °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 -2
Hawaii +78
Honolulu +78
Houston +44
Las Vegas +38
Los Angeles +50
Maui +72
Miami +68
Miami Beach +80
New York +16
San Diego +52
San Francisco +46
Sarasota +64
Tampa +62
Washington +26
24 Hours Weather Forecast
Duluth
Local time: 03:43
05 dec, friday
0600 18°F
NE
6 mph
0900 12°F
NE
5 mph
1200 20°F
NE
7 mph
1500 22°F
E
8 mph
1800 22°F
E
9 mph
2100 16°F
SE
12 mph
06 dec, saturday
0000 12°F
SE
11 mph
0300 8°F
SE
9 mph