S
M
T
W
T
F
S
30
87°
63°
31
88°
68°
1
91°
69°
2
93°
70°
3
93°
67°
4
86°
67°
5
83°
61°
6
81°
60°
7
80°
59°
8
79°
54°
9
80°
56°
10
83°
59°
11
78°
54°
12
78°
52°
13
76°
52°
14
78°
53°
15
81°
57°
16
81°
58°
17
80°
57°
18
79°
56°
19
81°
57°
20
81°
58°
21
80°
57°
22
81°
57°
23
81°
56°
24
80°
57°
25
81°
56°
26
80°
54°
27
79°
55°
28
79°
55°
29
78°
54°
30
77°
53°
1
77°
52°
2
76°
52°
3
77°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Mechanicsburg
Mechanicsburg's September 2026 forecast shows daily high temperatures ranging from 76° to 93°, with overnight lows between 51° and 70°. The average high for September is 81° with an average low of 57°. 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 Mechanicsburg. See also: October | November | December.
