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
72°
60°
20
69°
58°
21
69°
52°
22
60°
47°
23
61°
50°
24
61°
47°
25
65°
47°
26
66°
48°
27
69°
47°
28
67°
46°
29
69°
47°
30
70°
49°
1
69°
48°
2
68°
45°
3
63°
50°
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 60° to 72°, with overnight lows between 45° and 60°. The average high for September is 67° with an average low of 49°. 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.
