S
M
T
W
T
F
S
30
63°
51°
31
65°
53°
1
74°
52°
2
78°
60°
3
81°
63°
4
66°
58°
5
85°
60°
6
78°
55°
7
65°
59°
8
62°
56°
9
62°
50°
10
60°
58°
11
63°
55°
12
65°
56°
13
66°
60°
14
71°
57°
15
76°
60°
16
60°
56°
17
60°
55°
18
65°
50°
19
72°
60°
20
93°
58°
21
83°
61°
22
73°
52°
23
80°
55°
24
81°
55°
25
N/A
26
84°
62°
27
66°
57°
28
65°
50°
29
69°
51°
30
75°
55°
1
79°
59°
2
82°
61°
3
77°
57°
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 65° to 84°, with overnight lows between 50° and 62°. The average high for September is 75° 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.
