S
M
T
W
T
F
S
30
74°
55°
31
73°
55°
1
74°
59°
2
74°
62°
3
75°
63°
4
81°
63°
5
81°
62°
6
80°
55°
7
79°
55°
8
74°
56°
9
73°
54°
10
72°
54°
11
72°
56°
12
71°
55°
13
75°
57°
14
75°
59°
15
74°
59°
16
70°
58°
17
73°
57°
18
74°
58°
19
75°
51°
20
72°
54°
21
72°
51°
22
75°
49°
23
69°
49°
24
68°
50°
25
68°
52°
26
67°
49°
27
68°
50°
28
67°
51°
29
65°
47°
30
66°
47°
1
65°
53°
2
71°
49°
3
69°
49°
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 65° to 81°, with overnight lows between 47° and 63°. The average high for September is 72° with an average low of 54°. 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.
