S
M
T
W
T
F
S
30
80°
55°
31
74°
64°
1
70°
60°
2
74°
59°
3
80°
66°
4
83°
60°
5
77°
56°
6
74°
52°
7
76°
59°
8
80°
59°
9
73°
64°
10
78°
60°
11
74°
57°
12
76°
55°
13
74°
56°
14
76°
58°
15
79°
57°
16
78°
55°
17
74°
57°
18
69°
52°
19
73°
58°
20
74°
57°
21
71°
55°
22
69°
56°
23
70°
57°
24
74°
56°
25
69°
55°
26
72°
57°
27
74°
57°
28
73°
53°
29
65°
51°
30
65°
52°
1
64°
50°
2
64°
52°
3
63°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Charlestown
Charlestown's September 2026 forecast shows daily high temperatures ranging from 63° to 83°, with overnight lows between 50° and 66°. The average high for September is 73° with an average low of 56°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Charlestown. See also: October | November | December.
