S
M
T
W
T
F
S
30
84°
66°
31
84°
70°
1
86°
70°
2
84°
63°
3
83°
61°
4
80°
60°
5
81°
61°
6
82°
63°
7
83°
64°
8
84°
68°
9
87°
68°
10
83°
61°
11
82°
61°
12
81°
67°
13
82°
59°
14
82°
58°
15
78°
58°
16
80°
59°
17
79°
58°
18
80°
59°
19
83°
60°
20
83°
60°
21
85°
64°
22
84°
64°
23
77°
63°
24
80°
62°
25
80°
62°
26
83°
61°
27
83°
61°
28
82°
60°
29
83°
61°
30
83°
60°
1
82°
61°
2
83°
53°
3
82°
51°
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 77° to 87°, with overnight lows between 51° and 70°. The average high for September is 82° with an average low of 62°. 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.
