S
M
T
W
T
F
S
26
74°
51°
27
73°
48°
28
58°
44°
29
59°
41°
30
56°
38°
1
57°
35°
2
61°
33°
3
76°
49°
4
83°
46°
5
59°
40°
6
57°
36°
7
66°
37°
8
74°
44°
9
73°
46°
10
72°
38°
11
78°
39°
12
77°
51°
13
75°
49°
14
78°
50°
15
86°
56°
16
82°
59°
17
80°
61°
18
76°
61°
19
63°
46°
20
63°
41°
21
66°
49°
22
67°
51°
23
75°
54°
24
82°
51°
25
85°
60°
26
85°
60°
27
84°
61°
28
82°
57°
29
82°
56°
30
78°
51°
31
77°
53°
1
76°
55°
2
75°
53°
3
76°
55°
4
81°
59°
5
79°
56°
6
76°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Grinnell
Grinnell's May 2026 forecast shows daily high temperatures ranging from 75° to 85°, with overnight lows between 51° and 61°. The average high for May is 80° with an average low of 57°. 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 Grinnell. See also: June | July | August.
