S
M
T
W
T
F
S
30
79°
64°
31
86°
63°
1
87°
65°
2
85°
62°
3
84°
61°
4
84°
61°
5
73°
53°
6
71°
51°
7
77°
55°
8
76°
55°
9
75°
58°
10
76°
55°
11
72°
50°
12
72°
51°
13
74°
52°
14
76°
53°
15
78°
56°
16
78°
56°
17
77°
55°
18
79°
57°
19
78°
57°
20
77°
56°
21
77°
55°
22
76°
56°
23
78°
55°
24
77°
53°
25
71°
49°
26
69°
48°
27
71°
48°
28
73°
50°
29
74°
51°
30
74°
51°
1
73°
50°
2
74°
51°
3
74°
52°
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 69° to 87°, with overnight lows between 48° and 65°. The average high for September is 76° with an average low of 55°. 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.
