S
M
T
W
T
F
S
30
80°
55°
31
74°
64°
1
N/A
2
74°
64°
3
76°
63°
4
83°
59°
5
77°
56°
6
72°
58°
7
76°
59°
8
75°
59°
9
76°
61°
10
78°
60°
11
77°
59°
12
73°
59°
13
75°
56°
14
74°
57°
15
70°
57°
16
70°
59°
17
74°
57°
18
69°
54°
19
69°
54°
20
70°
58°
21
73°
59°
22
76°
59°
23
76°
58°
24
75°
57°
25
74°
56°
26
74°
56°
27
75°
57°
28
74°
56°
29
73°
55°
30
67°
50°
1
64°
51°
2
65°
54°
3
71°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Charlestown
Charlestown's September 2026 forecast shows daily high temperatures ranging from 64° to 83°, with overnight lows between 50° and 64°. The average high for September is 73° with an average low of 57°. 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.
