Measurements:
°C
°F
Dewey Beach
78°F
N 8 mph
Feels like: 80°F
Precip: 11%
World Resorts USA Dewey Beach Weather

Dewey Beach Sea Water Temperature

Current Sea Water Temperature:
+79.0°F
Maximum Sea Water Temperature in August: 85.8°F
Minimum Sea Water Temperature in August: 71.6°F
Average water temperature in August: 78.1°F

Sea Water Temperature for the Last 10 Days:

August 25 79.0°F August 20 81.6°F
August 24 79.2°F August 19 79.6°F
August 23 78.4°F August 18 80.2°F
August 22 78.8°F August 17 81.4°F
August 21 81.2°F August 16 80.8°F

When is the Warmest Sea for Dewey Beach?

According to our data for the last three years for Dewey Beach the highest average sea water temperature was in July, August and September.

Average Water Temperature by Month, °F

Sea Water Temperature in July

Select Year: 2026 2025 2024

The average sea surface temperature in July 2026 for Dewey Beach was 79.0°F. The maximum and minimum values were 75.2°F and 84.0°F respectively.

Sea Water Temperature in August

Select Year: 2026 2025 2024

The average sea surface temperature in August 2026 for Dewey Beach was 80.6°F. The maximum and minimum values were 77.2°F and 84.4°F respectively.

Sea Water Temperature in September

Select Year: 2025 2024 2023

The average sea surface temperature in September 2025 for Dewey Beach was 75.2°F. The maximum and minimum values were 73.2°F and 77.6°F respectively.

Best Time to Visit Dewey Beach
The most sunny months:
November 18 days
October 16 days
June 15 days
The most warm months:
July 84.1 °F
August 81.5 °F
June 77.6 °F
Warmest sea temperature:
July 78.3 °F
August 78.1 °F
September 75.6 °F
The most cold months:
January 39.5 °F
February 41.8 °F
December 45.1 °F
The most rainy months:
August 4 days
February 3 days
March 3 days
The most windy months:
March 13 mph
January 13 mph
February 12 mph

Dewey Beach on the Weather Map

USA Resorts:
NAME
Boston +80
Chicago +80
Hawaii +84
Houston +106
Las Vegas +116
Los Angeles +96
Maui +70
Miami +92
Myrtle Beach +84
New York +82
San Diego +96
San Francisco +64
Santa Monica +86
Sarasota +92
Washington +84
24 Hours Weather Forecast
Dewey Beach
Local time: 17:42
25 aug, tuesday
1800 78°F
N
8 mph
2100 78°F
N
9 mph
26 aug, wednesday
0000 76°F
NE
6 mph
0300 74°F
SE
3 mph
0600 74°F
W
2 mph
0900 74°F
SW
2 mph
1200 76°F
NW
8 mph
1500 76°F
NW
15 mph