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°
61°
10
93°
68°
11
93°
70°
12
88°
70°
13
90°
66°
14
92°
67°
15
85°
63°
16
85°
62°
17
87°
64°
18
90°
65°
19
88°
66°
20
87°
64°
21
77°
62°
22
77°
61°
23
77°
58°
24
77°
58°
25
78°
56°
26
80°
57°
27
83°
59°
28
83°
59°
29
83°
59°
30
82°
58°
1
79°
56°
2
82°
60°
3
83°
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 77° to 92°, with overnight lows between 56° and 67°. The average high for September is 83° with an average low of 61°. 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.
