Measurements:
°C
°F
Duluth
50°F
NW 7 mph
Feels like: 46°F
Precip: 0%
World Resorts USA Duluth Weather

Duluth Sea Water Temperature

Current Sea Water Temperature:
+41.0°F
Maximum Sea Water Temperature in May: 55.8°F
Minimum Sea Water Temperature in May: 32.4°F
Average water temperature in May: 40.8°F

Sea Water Temperature for the Last 10 Days:

May 14 41.0°F May 09 41.0°F
May 13 43.8°F May 08 39.6°F
May 12 42.8°F May 07 40.8°F
May 11 39.8°F May 06 37.8°F
May 10 39.8°F May 05 38.0°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 16.7 °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
Boston +62
Chicago +56
Hawaii +76
Honolulu +76
Houston +94
Las Vegas +88
Los Angeles +66
Maui +70
Miami +94
Miami Beach +90
New York +68
San Diego +66
San Francisco +62
Sarasota +94
Tampa +94
24 Hours Weather Forecast
Duluth
Local time: 12:01
14 may, thursday
1500 52°F
NW
8 mph
1800 52°F
NW
9 mph
2100 46°F
NW
9 mph
15 may, friday
0000 54°F
N
11 mph
0300 56°F
N
14 mph
0600 56°F
NE
12 mph
0900 64°F
NE
13 mph
1200 74°F
NE
16 mph