Measurements:
°C
°F
Duluth
58°F
E 18 mph
Feels like: 52°F
Precip: 16%
World Resorts USA Duluth Weather

Duluth Sea Water Temperature

Current Sea Water Temperature:
+63.8°F
Maximum Sea Water Temperature in September: 71.6°F
Minimum Sea Water Temperature in September: 52.4°F
Average water temperature in September: 64.0°F

Sea Water Temperature for the Last 10 Days:

September 15 63.8°F September 10 67.0°F
September 14 64.4°F September 09 67.4°F
September 13 64.8°F September 08 68.4°F
September 12 65.2°F September 07 67.2°F
September 11 64.6°F September 06 67.2°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: 2026 2025 2024

The average sea surface temperature in August 2026 for Duluth was 66.6°F. The maximum and minimum values were 61.6°F and 71.6°F respectively.

Sea Water Temperature in July

Select Year: 2026 2025 2024

The average sea surface temperature in July 2026 for Duluth was 66.0°F. The maximum and minimum values were 55.0°F and 75.8°F respectively.

Sea Water Temperature in September

Select Year: 2026 2025 2024

The average sea surface temperature in September 2026 for Duluth was 66.8°F. The maximum and minimum values were 63.8°F and 69.8°F respectively.

Best Time to Visit Duluth
The most sunny months:
August 14 days
September 14 days
July 13 days
The most warm months:
July 77.5 °F
August 75.8 °F
June 69.8 °F
Warmest sea temperature:
August 67.5 °F
July 65.5 °F
September 63.7 °F
The most cold months:
January 14.4 °F
February 16.7 °F
December 21.4 °F
The most rainy months:
August 3 days
July 3 days
June 2 days
The most windy months:
April 9 mph
March 8 mph
November 8 mph

Duluth on the Weather Map

USA Resorts:
NAME
Boston +62
Chicago +66
Hawaii +80
Las Vegas +80
Los Angeles +72
Maui +66
Miami +88
Myrtle Beach +78
New York +66
Panama City Beach +90
San Diego +70
San Francisco +60
Santa Monica +72
Sarasota +86
Washington +66
24 Hours Weather Forecast
Duluth
Local time: 08:38
15 sep, tuesday
0900 58°F
E
18 mph
1200 64°F
E
16 mph
1500 66°F
SE
14 mph
1800 68°F
E
6 mph
2100 60°F
SE
7 mph
16 sep, wednesday
0000 54°F
SE
6 mph
0300 50°F
S
4 mph
0600 48°F
S
2 mph