Measurements:
°C
°F
Duluth
82°F
W 6 mph
Feels like: 82°F
Precip: 2%
World Resorts USA Duluth Weather

Duluth Sea Water Temperature

Current Sea Water Temperature:
+70.6°F
Maximum Sea Water Temperature in July: 74.6°F
Minimum Sea Water Temperature in July: 48.4°F
Average water temperature in July: 65.3°F

Sea Water Temperature for the Last 10 Days:

July 15 70.6°F July 10 67.2°F
July 14 71.0°F July 09 66.4°F
July 13 71.8°F July 08 63.8°F
July 12 70.0°F July 07 63.4°F
July 11 67.6°F July 06 61.2°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: 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: 2026 2025 2024

The average sea surface temperature in July 2026 for Duluth was 64.5°F. The maximum and minimum values were 55.0°F and 71.8°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
August 13 days
July 12 days
The most warm months:
July 77.4 °F
August 76.5 °F
June 69.8 °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:
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 +96
Chicago +86
Hawaii +82
Houston +80
Las Vegas +118
Los Angeles +100
Maui +78
Miami +96
Myrtle Beach +90
New York +104
San Diego +94
San Francisco +82
Santa Monica +82
Sarasota +96
Tampa +98
24 Hours Weather Forecast
Duluth
Local time: 16:30
15 jul, wednesday
1800 82°F
SW
9 mph
2100 74°F
SW
6 mph
16 jul, thursday
0000 70°F
W
3 mph
0300 62°F
SW
2 mph
0600 60°F
SW
3 mph
0900 72°F
W
4 mph
1200 78°F
W
5 mph
1500 78°F
W
7 mph