S
M
T
W
T
F
S
26
59°
40°
27
58°
37°
28
60°
39°
29
60°
36°
30
58°
36°
1
61°
39°
2
62°
37°
3
61°
38°
4
63°
43°
5
71°
45°
6
70°
41°
7
66°
45°
8
73°
50°
9
74°
50°
10
74°
46°
11
64°
41°
12
63°
41°
13
65°
45°
14
64°
45°
15
65°
48°
16
66°
47°
17
65°
48°
18
75°
44°
19
69°
44°
20
70°
45°
21
68°
44°
22
68°
43°
23
67°
44°
24
68°
45°
25
70°
47°
26
70°
49°
27
71°
47°
28
71°
47°
29
72°
57°
30
72°
48°
31
77°
48°
1
71°
55°
2
73°
50°
3
78°
49°
4
74°
56°
5
79°
49°
6
75°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Lehigh Valley
Lehigh Valley's May 2026 forecast shows daily high temperatures ranging from 58° to 79°, with overnight lows between 36° and 57°. The average high for May is 68° with an average low of 45°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how May weather will actually feel in Lehigh Valley. See also: June | July | August.