Measurements:
°C
°F
Dewey Beach
46°F
N 30 mph
Feels like: 38°F
Precip: 0%
World Resorts USA Dewey Beach Weather

Dewey Beach Sea Water Temperature

Current Sea Water Temperature:
+40.6°F
Maximum Sea Water Temperature in March: 50.6°F
Minimum Sea Water Temperature in March: 34.0°F
Average water temperature in March: 44.0°F

Sea Water Temperature for the Last 10 Days:

March 13 40.6°F March 08 35.8°F
March 12 41.4°F March 07 35.2°F
March 11 39.8°F March 06 35.6°F
March 10 39.8°F March 05 35.6°F
March 09 36.2°F March 04 35.2°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: 2025 2024 2023

The average sea surface temperature in July 2025 for Dewey Beach was 80.7°F. The maximum and minimum values were 77.2°F and 83.4°F respectively.

Sea Water Temperature in August

Select Year: 2025 2024 2023

The average sea surface temperature in August 2025 for Dewey Beach was 79.4°F. The maximum and minimum values were 76.8°F and 85.8°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
January 14 days
The most warm months:
July 84.2 °F
August 81.5 °F
June 77.7 °F
Warmest sea temperature:
July 78.2 °F
August 77.7 °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
Chicago +42
Hawaii +76
Honolulu +76
Houston +82
Las Vegas +96
Los Angeles +100
Maui +70
Miami +84
Miami Beach +82
New York +42
San Diego +94
San Francisco +72
Sarasota +80
Tampa +80
Washington +56
24 Hours Weather Forecast
Dewey Beach
Local time: 17:00
13 mar, friday
1800 46°F
N
30 mph
2100 42°F
NE
24 mph
14 mar, saturday
0000 44°F
NE
24 mph
0300 42°F
NE
17 mph
0600 42°F
E
16 mph
0900 46°F
E
22 mph
1200 48°F
E
25 mph
1500 50°F
SE
22 mph