S
M
T
W
T
F
S
30
75°
48°
31
76°
47°
1
74°
47°
2
73°
49°
3
74°
50°
4
72°
51°
5
74°
49°
6
73°
48°
7
71°
47°
8
72°
46°
9
70°
46°
10
72°
52°
11
71°
46°
12
71°
45°
13
75°
44°
14
73°
51°
15
74°
51°
16
71°
45°
17
68°
43°
18
71°
43°
19
72°
49°
20
74°
50°
21
74°
49°
22
69°
47°
23
73°
47°
24
71°
44°
25
69°
47°
26
65°
40°
27
71°
41°
28
63°
40°
29
62°
40°
30
64°
42°
1
64°
38°
2
61°
36°
3
Hist. Avg.
64°
41°
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 61° to 76°, with overnight lows between 36° and 52°. The average high for September is 71° with an average low of 46°. 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.
