19.09
sat
sat
Day
63°F
SW 9 mph
Precip.
8%
8%
Night
59°F
NW 11 mph
Precip.
16%
16%
20.09
sun
sun
Day
63°F
NW 9 mph
Precip.
17%
17%
Night
64°F
NW 13 mph
Precip.
83%
83%
21.09
mon
mon
Day
59°F
SW 22 mph
Precip.
37%
37%
Night
61°F
SW 19 mph
Precip.
20%
20%
22.09
tue
tue
Day
57°F
SW 25 mph
Precip.
26%
26%
Night
55°F
W 22 mph
Precip.
71%
71%
23.09
wed
wed
Day
63°F
W 29 mph
Precip.
22%
22%
Night
61°F
SW 25 mph
Precip.
20%
20%
24.09
thu
thu
Day
59°F
SW 27 mph
Precip.
73%
73%
Night
57°F
SW 24 mph
Precip.
41%
41%
25.09
fri
fri
Day
59°F
SW 17 mph
Precip.
13%
13%
Night
59°F
SW 9 mph
Precip.
14%
14%
sea water
temperature
temperature
| Charlestown |
monthly
weather
weather
| Charlestown |
current
weather
weather
| Charlestown |
14 days
forecast
forecast
| Charlestown |
Sea water temperature in September, °F
Show year:
2026
2025
2024
The average sea water temperature in September of 2026 was 69.2°F. The highest and lowest sea temperatures during the month were 70.3°F and 68.4°F.
Sea water temperature in October, °F
Show year:
2025
2024
2023
The average sea water temperature in October of 2025 was 64.4°F. The highest and lowest sea temperatures during the month were 68.4°F and 59.9°F.
Air temperature in Charlestown, °F
Precipitation total in Charlestown, in.
* Charts above show average data for the last 3 years.
Best time for vacation in Charlestown
Charlestown on a weather map
Places in USA:
Name
°F
24 Hours Forecast
Charlestown
Local time: 05:24
September 19, saturday
0600
57°F
SW
13 mph
13 mph
0900
59°F
SW
14 mph
14 mph
1200
63°F
SW
9 mph
9 mph
1500
63°F
NW
10 mph
10 mph
1800
61°F
W
9 mph
9 mph
2100
61°F
W
11 mph
11 mph
September 20, sunday
0000
59°F
NW
11 mph
11 mph
0300
59°F
NW
9 mph
9 mph
