S
M
T
W
T
F
S
30
81°
59°
31
82°
60°
1
82°
60°
2
81°
59°
3
83°
60°
4
82°
60°
5
81°
58°
6
81°
59°
7
80°
59°
8
82°
58°
9
82°
57°
10
80°
58°
11
80°
58°
12
81°
57°
13
80°
58°
14
78°
58°
15
77°
56°
16
78°
54°
17
74°
54°
18
73°
52°
19
69°
50°
20
74°
53°
21
77°
49°
22
73°
45°
23
66°
44°
24
68°
49°
25
66°
51°
26
75°
51°
27
76°
49°
28
71°
50°
29
70°
51°
30
73°
42°
1
70°
40°
2
63°
39°
3
62°
41°
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 62° to 83°, with overnight lows between 39° and 60°. The average high for September is 76° with an average low of 53°. 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.
