S
M
T
W
T
F
S
26
69°
42°
27
67°
48°
28
61°
48°
29
51°
41°
30
48°
36°
1
46°
38°
2
49°
32°
3
58°
40°
4
74°
51°
5
52°
42°
6
55°
35°
7
54°
35°
8
62°
33°
9
65°
47°
10
59°
35°
11
57°
36°
12
65°
31°
13
54°
42°
14
60°
39°
15
72°
39°
16
77°
57°
17
86°
60°
18
82°
66°
19
78°
56°
20
62°
49°
21
64°
44°
22
71°
46°
23
62°
51°
24
72°
49°
25
83°
60°
26
89°
61°
27
89°
61°
28
75°
53°
29
79°
50°
30
72°
48°
31
73°
53°
1
73°
54°
2
74°
55°
3
75°
58°
4
76°
57°
5
74°
52°
6
73°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Grand Valley
Grand Valley's May 2026 forecast shows daily high temperatures ranging from 62° to 89°, with overnight lows between 48° and 61°. The average high for May is 76° with an average low of 55°. 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 Grand Valley. See also: June | July | August.
