S
M
T
W
T
F
S
26
46°
41°
27
55°
39°
28
61°
45°
29
68°
48°
30
73°
52°
1
75°
57°
2
70°
61°
3
64°
48°
4
50°
45°
5
50°
45°
6
66°
50°
7
73°
54°
8
77°
55°
9
79°
57°
10
81°
58°
11
86°
65°
12
83°
57°
13
74°
52°
14
73°
52°
15
72°
49°
16
68°
48°
17
70°
50°
18
69°
52°
19
68°
50°
20
69°
52°
21
72°
48°
22
67°
46°
23
70°
48°
24
72°
48°
25
73°
49°
26
72°
47°
27
75°
48°
28
72°
47°
29
77°
53°
30
79°
54°
31
79°
54°
1
78°
53°
2
79°
54°
3
75°
51°
4
71°
52°
5
71°
51°
6
72°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Grass Valley
Grass Valley's May 2026 forecast shows daily high temperatures ranging from 67° to 86°, with overnight lows between 46° and 65°. The average high for May is 74° with an average low of 52°. 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 Grass Valley. See also: June | July | August.
