S
M
T
W
T
F
S
26
40°
18°
27
44°
22°
28
47°
17°
29
49°
20°
30
55°
21°
1
69°
27°
2
67°
37°
3
74°
33°
4
42°
27°
5
45°
27°
6
53°
24°
7
59°
33°
8
65°
35°
9
65°
35°
10
67°
39°
11
71°
40°
12
71°
41°
13
67°
40°
14
67°
39°
15
68°
40°
16
66°
40°
17
70°
44°
18
70°
46°
19
61°
46°
20
61°
40°
21
60°
36°
22
62°
43°
23
65°
43°
24
62°
44°
25
62°
45°
26
63°
40°
27
63°
40°
28
66°
45°
29
65°
47°
30
64°
44°
31
72°
50°
1
74°
51°
2
76°
52°
3
76°
52°
4
77°
53°
5
75°
52°
6
73°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Portal
Portal's May 2026 forecast shows daily high temperatures ranging from 42° to 77°, with overnight lows between 24° and 53°. The average high for May is 66° with an average low of 42°. 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 Portal. See also: June | July | August.
