S
M
T
W
T
F
S
26
61°
41°
27
70°
37°
28
61°
43°
29
63°
46°
30
61°
46°
1
63°
37°
2
59°
45°
3
61°
43°
4
73°
41°
5
82°
54°
6
70°
52°
7
64°
48°
8
63°
41°
9
61°
50°
10
70°
48°
11
63°
46°
12
66°
39°
13
70°
54°
14
61°
50°
15
64°
50°
16
81°
45°
17
86°
61°
18
93°
63°
19
93°
70°
20
90°
63°
21
63°
54°
22
68°
54°
23
54°
46°
24
59°
50°
25
76°
54°
26
82°
63°
27
82°
60°
28
75°
52°
29
74°
46°
30
69°
47°
31
73°
53°
1
73°
49°
2
72°
53°
3
77°
57°
4
80°
60°
5
81°
58°
6
83°
60°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Allentown
Allentown's May 2026 forecast shows daily high temperatures ranging from 69° to 83°, with overnight lows between 46° and 63°. The average high for May is 77° 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 May weather will actually feel in Allentown. See also: June | July | August.
