S
M
T
W
T
F
S
26
70°
49°
27
67°
44°
28
56°
39°
29
57°
40°
30
54°
35°
1
54°
34°
2
63°
29°
3
72°
46°
4
72°
44°
5
55°
34°
6
52°
30°
7
62°
31°
8
74°
33°
9
65°
41°
10
69°
32°
11
69°
30°
12
79°
54°
13
74°
43°
14
78°
44°
15
90°
50°
16
80°
53°
17
74°
60°
18
68°
60°
19
56°
39°
20
61°
45°
21
59°
47°
22
57°
49°
23
68°
49°
24
78°
57°
25
77°
54°
26
79°
58°
27
77°
56°
28
78°
58°
29
79°
57°
30
77°
57°
31
78°
59°
1
75°
53°
2
75°
58°
3
71°
55°
4
71°
55°
5
75°
59°
6
75°
60°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Mason City
Mason City's May 2026 forecast shows daily high temperatures ranging from 56° to 79°, with overnight lows between 39° and 60°. The average high for May is 72° with an average low of 54°. 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 Mason City. See also: June | July | August.
