S
M
T
W
T
F
S
30
80°
61°
31
82°
64°
1
85°
64°
2
85°
63°
3
84°
57°
4
84°
55°
5
78°
56°
6
78°
62°
7
79°
62°
8
82°
61°
9
83°
60°
10
79°
61°
11
82°
60°
12
82°
61°
13
81°
61°
14
81°
60°
15
83°
61°
16
83°
59°
17
81°
60°
18
80°
55°
19
80°
52°
20
75°
51°
21
73°
49°
22
72°
56°
23
73°
54°
24
78°
49°
25
71°
49°
26
71°
51°
27
72°
50°
28
76°
54°
29
75°
53°
30
76°
52°
1
70°
53°
2
69°
46°
3
73°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Adelphia
Adelphia's September 2026 forecast shows daily high temperatures ranging from 69° to 85°, with overnight lows between 46° and 64°. The average high for September is 78° with an average low of 56°. 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 Adelphia. See also: October | November | December.