S
M
T
W
T
F
S
30
88°
78°
31
88°
77°
1
87°
78°
2
87°
78°
3
86°
79°
4
89°
78°
5
88°
79°
6
89°
78°
7
89°
78°
8
88°
77°
9
89°
77°
10
86°
78°
11
86°
77°
12
87°
75°
13
86°
77°
14
87°
77°
15
87°
78°
16
86°
78°
17
87°
77°
18
88°
78°
19
87°
77°
20
88°
77°
21
87°
78°
22
87°
79°
23
88°
78°
24
Hist. Avg.
86°
77°
25
Hist. Avg.
86°
77°
26
Hist. Avg.
86°
77°
27
Hist. Avg.
86°
77°
28
Hist. Avg.
86°
77°
29
Hist. Avg.
86°
77°
30
Hist. Avg.
86°
77°
1
Hist. Avg.
86°
77°
2
Hist. Avg.
86°
77°
3
Hist. Avg.
86°
77°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Capitol Hill
Capitol Hill's September 2026 forecast shows daily high temperatures ranging from 86° to 89°, with overnight lows between 75° and 79°. The average high for September is 87° with an average low of 78°. 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 Capitol Hill. See also: October | November | December.
