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
81°
62°
14
72°
47°
15
72°
52°
16
78°
62°
17
82°
64°
18
79°
56°
19
72°
58°
20
69°
53°
21
70°
49°
22
66°
52°
23
67°
48°
24
70°
50°
25
72°
51°
26
71°
47°
27
74°
52°
28
74°
52°
29
74°
49°
30
69°
45°
1
67°
50°
2
69°
50°
3
71°
45°
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 66° to 82°, with overnight lows between 45° and 64°. The average high for September is 72° with an average low of 52°. 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.
