S
M
T
W
T
F
S
30
82°
64°
31
82°
64°
1
83°
60°
2
76°
56°
3
75°
56°
4
75°
57°
5
76°
56°
6
80°
62°
7
82°
62°
8
81°
61°
9
81°
62°
10
82°
62°
11
82°
61°
12
81°
62°
13
82°
63°
14
82°
54°
15
72°
52°
16
69°
51°
17
71°
52°
18
70°
51°
19
69°
49°
20
69°
49°
21
77°
51°
22
76°
55°
23
77°
48°
24
76°
47°
25
68°
46°
26
70°
49°
27
71°
55°
28
74°
54°
29
72°
45°
30
66°
44°
1
65°
52°
2
66°
50°
3
71°
50°
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 65° to 83°, with overnight lows between 44° and 64°. The average high for September is 75° with an average low of 55°. 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.
