S
M
T
W
T
F
S
26
61°
41°
27
71°
35°
28
60°
39°
29
62°
48°
30
61°
45°
1
63°
36°
2
59°
44°
3
60°
42°
4
72°
40°
5
82°
51°
6
70°
51°
7
64°
47°
8
62°
45°
9
58°
46°
10
72°
47°
11
59°
40°
12
60°
37°
13
58°
43°
14
61°
41°
15
65°
46°
16
70°
46°
17
69°
47°
18
73°
51°
19
77°
54°
20
77°
54°
21
76°
49°
22
66°
46°
23
67°
46°
24
67°
45°
25
69°
50°
26
72°
51°
27
69°
48°
28
72°
48°
29
69°
46°
30
73°
51°
31
77°
55°
1
75°
55°
2
76°
51°
3
77°
56°
4
79°
57°
5
79°
57°
6
78°
58°
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 37° and 58°. The average high for May is 70° with an average low of 49°. 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.