S
M
T
W
T
F
S
26
66°
28°
27
69°
33°
28
69°
36°
29
75°
41°
30
77°
43°
1
79°
39°
2
83°
48°
3
86°
47°
4
86°
48°
5
84°
53°
6
85°
47°
7
82°
52°
8
78°
50°
9
77°
46°
10
78°
46°
11
77°
43°
12
83°
46°
13
68°
52°
14
68°
43°
15
60°
36°
16
58°
35°
17
71°
37°
18
72°
39°
19
73°
39°
20
78°
44°
21
77°
52°
22
82°
51°
23
85°
54°
24
79°
50°
25
72°
49°
26
67°
50°
27
79°
52°
28
78°
51°
29
81°
52°
30
79°
50°
31
80°
50°
1
81°
52°
2
77°
50°
3
70°
45°
4
73°
53°
5
71°
51°
6
71°
46°
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 67° to 85°, with overnight lows between 44° and 54°. The average high for May is 77° with an average low of 50°. 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.
