S
M
T
W
T
F
S
26
45°
28°
27
48°
28°
28
49°
31°
29
52°
33°
30
52°
34°
1
54°
33°
2
51°
33°
3
51°
35°
4
54°
34°
5
59°
32°
6
51°
26°
7
52°
27°
8
52°
31°
9
53°
33°
10
52°
33°
11
52°
30°
12
53°
28°
13
54°
30°
14
56°
33°
15
56°
36°
16
63°
40°
17
56°
37°
18
56°
33°
19
57°
34°
20
60°
37°
21
62°
39°
22
61°
38°
23
59°
35°
24
56°
32°
25
57°
36°
26
57°
36°
27
59°
38°
28
61°
38°
29
68°
42°
30
70°
43°
31
67°
40°
1
69°
41°
2
58°
33°
3
64°
40°
4
70°
43°
5
68°
40°
6
73°
46°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Sun Valley
Sun Valley's May 2026 forecast shows daily high temperatures ranging from 45° to 73°, with overnight lows between 26° and 46°. The average high for May is 58° with an average low of 35°. 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 Sun Valley. See also: June | July | August.
