S
M
T
W
T
F
S
30
94°
72°
31
96°
73°
1
96°
73°
2
95°
72°
3
96°
73°
4
96°
74°
5
95°
74°
6
96°
72°
7
96°
66°
8
87°
66°
9
88°
68°
10
90°
68°
11
92°
70°
12
93°
70°
13
92°
69°
14
93°
70°
15
92°
66°
16
92°
62°
17
85°
62°
18
84°
67°
19
84°
59°
20
87°
59°
21
83°
60°
22
81°
58°
23
82°
59°
24
83°
60°
25
83°
62°
26
84°
64°
27
87°
66°
28
86°
67°
29
88°
64°
30
87°
64°
1
81°
62°
2
86°
56°
3
80°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Keene
Keene's September 2026 forecast shows daily high temperatures ranging from 80° to 96°, with overnight lows between 56° and 74°. The average high for September is 89° with an average low of 66°. 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 Keene. See also: October | November | December.
