S
M
T
W
T
F
S
26
57°
39°
27
62°
42°
28
56°
46°
29
60°
43°
30
61°
44°
1
58°
41°
2
54°
39°
3
58°
41°
4
58°
39°
5
62°
44°
6
68°
42°
7
66°
46°
8
62°
41°
9
63°
40°
10
63°
40°
11
64°
43°
12
63°
45°
13
63°
44°
14
64°
46°
15
64°
45°
16
65°
44°
17
64°
43°
18
64°
44°
19
65°
45°
20
64°
45°
21
66°
44°
22
67°
47°
23
68°
53°
24
74°
54°
25
71°
49°
26
68°
46°
27
68°
46°
28
69°
54°
29
69°
55°
30
70°
56°
31
71°
56°
1
72°
55°
2
73°
56°
3
71°
57°
4
75°
55°
5
79°
49°
6
74°
50°
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 54° to 79°, with overnight lows between 39° and 57°. The average high for May is 66° with an average low of 47°. 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.