S
M
T
W
T
F
S
26
56°
41°
27
61°
30°
28
63°
25°
29
66°
30°
30
67°
32°
1
60°
31°
2
66°
27°
3
70°
28°
4
66°
42°
5
65°
44°
6
59°
31°
7
70°
21°
8
80°
35°
9
80°
34°
10
77°
29°
11
82°
34°
12
87°
36°
13
85°
40°
14
72°
45°
15
75°
47°
16
74°
43°
17
65°
38°
18
59°
31°
19
60°
36°
20
67°
40°
21
73°
41°
22
75°
42°
23
68°
43°
24
68°
43°
25
69°
45°
26
73°
43°
27
68°
37°
28
60°
34°
29
62°
37°
30
66°
41°
31
70°
42°
1
72°
43°
2
73°
43°
3
73°
44°
4
74°
46°
5
73°
45°
6
70°
44°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Vallecito
Vallecito's May 2026 forecast shows daily high temperatures ranging from 59° to 75°, with overnight lows between 31° and 47°. The average high for May is 69° with an average low of 41°. 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 Vallecito. See also: June | July | August.