S
M
T
W
T
F
S
30
89°
58°
31
89°
56°
1
87°
60°
2
92°
53°
3
95°
54°
4
96°
59°
5
98°
57°
6
92°
58°
7
92°
64°
8
88°
59°
9
79°
56°
10
90°
44°
11
94°
52°
12
76°
49°
13
84°
51°
14
88°
60°
15
74°
49°
16
88°
53°
17
72°
57°
18
86°
59°
19
80°
54°
20
72°
48°
21
71°
51°
22
74°
57°
23
77°
52°
24
76°
53°
25
78°
53°
26
84°
55°
27
78°
50°
28
73°
47°
29
69°
46°
30
70°
49°
1
70°
46°
2
67°
42°
3
69°
44°
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 67° to 84°, with overnight lows between 42° and 57°. The average high for September is 73° with an average low of 50°. 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.
