Measurements:
°C
°F
Duluth
70°F
SW 9 mph
Feels like: 70°F
Precip: 13%
World Resorts USA Duluth Weather

Duluth Sea Water Temperature

Current Sea Water Temperature:
+65.6°F
Maximum Sea Water Temperature in August: 73.8°F
Minimum Sea Water Temperature in August: 53.6°F
Average water temperature in August: 67.4°F

Sea Water Temperature for the Last 10 Days:

August 25 65.6°F August 20 66.0°F
August 24 65.4°F August 19 67.8°F
August 23 65.0°F August 18 68.0°F
August 22 65.8°F August 17 67.4°F
August 21 64.8°F August 16 70.4°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: 2026 2025 2024

The average sea surface temperature in August 2026 for Duluth was 66.5°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: 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
July 13 days
August 13 days
The most warm months:
July 77.5 °F
August 76.5 °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 +80
Chicago +78
Hawaii +84
Houston +106
Las Vegas +116
Los Angeles +96
Maui +70
Miami +90
Myrtle Beach +84
New York +86
San Diego +96
San Francisco +74
Santa Monica +86
Sarasota +92
Washington +88
24 Hours Weather Forecast
Duluth
Local time: 16:54
25 aug, tuesday
1800 70°F
SW
9 mph
2100 68°F
SW
8 mph
26 aug, wednesday
0000 66°F
NE
3 mph
0300 64°F
E
6 mph
0600 62°F
E
7 mph
0900 66°F
E
8 mph
1200 76°F
SE
9 mph
1500 78°F
S
11 mph