S
M
T
W
T
F
S
30
88°
68°
31
89°
66°
1
84°
67°
2
84°
67°
3
85°
66°
4
84°
67°
5
83°
66°
6
83°
66°
7
88°
65°
8
83°
60°
9
83°
59°
10
82°
64°
11
82°
60°
12
87°
59°
13
86°
65°
14
87°
58°
15
84°
57°
16
79°
56°
17
80°
57°
18
83°
58°
19
85°
57°
20
85°
57°
21
84°
60°
22
85°
61°
23
84°
55°
24
81°
57°
25
84°
54°
26
83°
59°
27
83°
59°
28
82°
58°
29
83°
59°
30
83°
58°
1
80°
58°
2
82°
57°
3
83°
57°
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 79° to 89°, with overnight lows between 54° and 68°. The average high for September is 84° with an average low of 60°. 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.
