S
M
T
W
T
F
S
26
54°
42°
27
59°
44°
28
62°
46°
29
63°
44°
30
66°
48°
1
68°
47°
2
67°
45°
3
64°
44°
4
63°
46°
5
65°
47°
6
68°
45°
7
69°
45°
8
63°
44°
9
62°
43°
10
62°
43°
11
63°
44°
12
64°
44°
13
64°
42°
14
65°
42°
15
67°
47°
16
65°
48°
17
63°
46°
18
65°
46°
19
66°
47°
20
69°
49°
21
73°
50°
22
75°
51°
23
76°
52°
24
76°
53°
25
77°
53°
26
78°
54°
27
78°
54°
28
76°
53°
29
78°
53°
30
77°
49°
31
70°
47°
1
69°
45°
2
70°
48°
3
71°
48°
4
75°
51°
5
77°
49°
6
79°
50°
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 54° to 79°, with overnight lows between 42° and 54°. The average high for May is 69° with an average low of 47°. 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.
