S
M
T
W
T
F
S
26
80°
45°
27
69°
59°
28
62°
53°
29
61°
43°
30
63°
37°
1
60°
41°
2
59°
41°
3
73°
42°
4
78°
56°
5
59°
47°
6
61°
40°
7
68°
39°
8
66°
50°
9
79°
51°
10
70°
47°
11
74°
43°
12
83°
50°
13
73°
48°
14
73°
42°
15
80°
52°
16
78°
65°
17
85°
67°
18
77°
64°
19
77°
57°
20
71°
52°
21
74°
50°
22
69°
57°
23
78°
61°
24
80°
59°
25
83°
54°
26
84°
58°
27
88°
65°
28
90°
59°
29
81°
62°
30
79°
59°
31
79°
58°
1
86°
56°
2
83°
58°
3
83°
59°
4
83°
65°
5
82°
64°
6
84°
62°
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 79° to 90°, with overnight lows between 56° and 65°. The average high for May is 83° with an average low of 60°. 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.
