S
M
T
W
T
F
S
30
82°
63°
31
84°
63°
1
86°
61°
2
90°
61°
3
91°
57°
4
91°
63°
5
93°
66°
6
91°
63°
7
91°
68°
8
82°
64°
9
81°
57°
10
90°
54°
11
90°
64°
12
85°
61°
13
94°
67°
14
87°
57°
15
72°
54°
16
81°
57°
17
81°
57°
18
81°
55°
19
78°
57°
20
80°
54°
21
80°
54°
22
79°
55°
23
81°
57°
24
82°
56°
25
78°
48°
26
77°
49°
27
81°
52°
28
76°
51°
29
77°
50°
30
74°
48°
1
79°
50°
2
78°
50°
3
79°
46°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Capitol Hill
Capitol Hill's September 2026 forecast shows daily high temperatures ranging from 72° to 94°, with overnight lows between 46° and 67°. The average high for September is 80° with an average low of 54°. 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.
