S
M
T
W
T
F
S
30
83°
55°
31
82°
58°
1
82°
58°
2
81°
57°
3
81°
58°
4
80°
57°
5
80°
57°
6
79°
56°
7
79°
56°
8
78°
55°
9
79°
56°
10
79°
55°
11
78°
55°
12
80°
54°
13
80°
56°
14
79°
56°
15
79°
55°
16
78°
55°
17
77°
54°
18
75°
53°
19
73°
44°
20
69°
52°
21
70°
53°
22
71°
44°
23
69°
44°
24
68°
45°
25
70°
50°
26
73°
51°
27
68°
45°
28
67°
44°
29
66°
44°
30
66°
48°
1
67°
51°
2
68°
43°
3
67°
40°
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 83°, with overnight lows between 40° and 58°. The average high for September is 75° 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.
