Measurements:
°C
°F
Charlestown
60°F
SE 12 mph
Feels like: 58°F
Precip: 19%
World Resorts USA Charlestown Weather

Charlestown Sea Water Temperature

Current Sea Water Temperature:
+60.0°F
Maximum Sea Water Temperature in October: 70.4°F
Minimum Sea Water Temperature in October: 60.0°F
Average water temperature in October: 64.7°F

Sea Water Temperature for the Last 10 Days:

October 26 60.0°F October 21 61.4°F
October 25 60.6°F October 20 62.2°F
October 24 60.4°F October 19 62.8°F
October 23 60.8°F October 18 62.4°F
October 22 61.0°F October 17 63.8°F

When is the Warmest Sea for Charlestown?

According to our data for the last three years for Charlestown 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 Charlestown was 72.9°F. The maximum and minimum values were 71.6°F and 75.2°F respectively.

Sea Water Temperature in July

Select Year: 2026 2025 2024

The average sea surface temperature in July 2026 for Charlestown was 70.6°F. The maximum and minimum values were 68.2°F and 72.6°F respectively.

Sea Water Temperature in September

Select Year: 2026 2025 2024

The average sea surface temperature in September 2026 for Charlestown was 70.2°F. The maximum and minimum values were 63.6°F and 72.6°F respectively.

Best Time to Visit Charlestown
The most sunny months:
November 17 days
October 13 days
December 13 days
The most warm months:
July 78.9 °F
August 77.8 °F
September 71.8 °F
Warmest sea temperature:
August 73.1 °F
July 71.6 °F
September 70.5 °F
The most cold months:
January 35.0 °F
February 35.5 °F
December 41.0 °F
The most rainy months:
November 3 days
October 3 days
January 2 days
The most windy months:
January 13 mph
December 13 mph
March 12 mph

Charlestown on the Weather Map

USA Resorts:
NAME
F°
Boston +58
Chicago +58
Hawaii +80
Houston +74
Las Vegas +64
Los Angeles +74
Maui +72
Miami +82
New York +62
Panama City Beach +64
San Diego +74
San Francisco +60
Santa Monica +72
Tampa +72
Washington +58
24 Hours Weather Forecast
Charlestown
Local time: 00:46
27 oct, tuesday
0300 56°F
S
14 mph
0600 50°F
S
14 mph
0900 48°F
S
14 mph
1200 54°F
SW
11 mph
1500 56°F
W
4 mph
1800 52°F
N
6 mph
2100 52°F
NW
4 mph
28 oct, wednesday
0000 52°F
NW
4 mph