S
M
T
W
T
F
S
30
81°
56°
31
76°
66°
1
88°
68°
2
73°
68°
3
87°
67°
4
83°
70°
5
80°
62°
6
78°
58°
7
78°
53°
8
82°
53°
9
85°
59°
10
86°
69°
11
81°
57°
12
80°
52°
13
82°
66°
14
73°
52°
15
74°
45°
16
83°
55°
17
80°
68°
18
82°
60°
19
73°
59°
20
70°
60°
21
70°
57°
22
68°
54°
23
67°
50°
24
67°
46°
25
75°
46°
26
65°
56°
27
65°
57°
28
63°
56°
29
71°
50°
30
73°
56°
1
77°
61°
2
73°
52°
3
66°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Lehigh Valley
Lehigh Valley's September 2026 forecast shows daily high temperatures ranging from 63° to 77°, with overnight lows between 49° and 61°. The average high for September is 70° with an average low of 54°. 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 Lehigh Valley. See also: October | November | December.
