S
M
T
W
T
F
S
26
61°
44°
27
60°
40°
28
63°
41°
29
62°
40°
30
61°
40°
1
63°
43°
2
64°
42°
3
63°
41°
4
65°
46°
5
73°
50°
6
73°
44°
7
68°
47°
8
75°
53°
9
76°
54°
10
77°
49°
11
67°
45°
12
65°
44°
13
67°
48°
14
66°
49°
15
67°
52°
16
66°
51°
17
68°
51°
18
77°
47°
19
71°
48°
20
74°
48°
21
71°
47°
22
70°
46°
23
69°
47°
24
71°
47°
25
72°
51°
26
73°
52°
27
73°
50°
28
74°
50°
29
74°
60°
30
75°
52°
31
79°
52°
1
74°
59°
2
75°
54°
3
79°
53°
4
77°
59°
5
81°
53°
6
79°
54°
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 60° to 81°, with overnight lows between 40° and 60°. 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.