S
M
T
W
T
F
S
30
79°
62°
31
80°
63°
1
84°
57°
2
79°
57°
3
79°
58°
4
78°
56°
5
78°
55°
6
81°
59°
7
81°
59°
8
79°
61°
9
83°
60°
10
80°
60°
11
80°
59°
12
82°
59°
13
82°
60°
14
81°
59°
15
82°
58°
16
81°
54°
17
79°
57°
18
72°
59°
19
79°
58°
20
80°
58°
21
79°
56°
22
78°
49°
23
76°
54°
24
73°
55°
25
Hist. Avg.
74°
52°
26
Hist. Avg.
74°
51°
27
Hist. Avg.
73°
51°
28
Hist. Avg.
73°
51°
29
Hist. Avg.
72°
50°
30
Hist. Avg.
72°
50°
1
Hist. Avg.
71°
49°
2
Hist. Avg.
71°
49°
3
Hist. Avg.
71°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Lehigh Valley
Lehigh Valley's September 2026 forecast shows daily high temperatures ranging from 72° to 84°, with overnight lows between 49° and 63°. The average high for September is 79° with an average low of 58°. 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.
