S
M
T
W
T
F
S
30
90°
68°
31
90°
67°
1
85°
67°
2
84°
66°
3
84°
67°
4
85°
67°
5
84°
66°
6
84°
66°
7
86°
65°
8
83°
61°
9
83°
60°
10
84°
62°
11
82°
61°
12
86°
63°
13
86°
65°
14
87°
59°
15
85°
58°
16
80°
57°
17
81°
58°
18
83°
59°
19
85°
57°
20
85°
57°
21
84°
59°
22
84°
61°
23
83°
57°
24
82°
56°
25
83°
54°
26
83°
55°
27
82°
59°
28
83°
59°
29
83°
58°
30
84°
58°
1
82°
57°
2
82°
59°
3
83°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Harrisburg
Harrisburg's September 2026 forecast shows daily high temperatures ranging from 80° to 90°, with overnight lows between 54° and 68°. The average high for September is 84° with an average low of 61°. 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 Harrisburg. See also: October | November | December.
