S
M
T
W
T
F
S
30
84°
70°
31
91°
66°
1
94°
70°
2
97°
72°
3
97°
72°
4
95°
75°
5
97°
72°
6
82°
70°
7
82°
64°
8
84°
63°
9
88°
67°
10
91°
71°
11
92°
70°
12
83°
68°
13
88°
70°
14
91°
69°
15
90°
68°
16
89°
65°
17
84°
62°
18
83°
62°
19
80°
58°
20
80°
56°
21
79°
59°
22
80°
58°
23
85°
62°
24
83°
62°
25
82°
57°
26
80°
57°
27
83°
59°
28
84°
61°
29
84°
61°
30
83°
60°
1
82°
60°
2
82°
58°
3
81°
59°
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 92°, with overnight lows between 56° and 71°. The average high for September is 84° 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.
