S
M
T
W
T
F
S
26
67°
51°
27
70°
48°
28
75°
50°
29
74°
55°
30
72°
55°
1
74°
54°
2
74°
57°
3
72°
55°
4
74°
53°
5
77°
55°
6
77°
54°
7
76°
55°
8
75°
54°
9
78°
57°
10
77°
55°
11
76°
56°
12
77°
58°
13
78°
58°
14
79°
59°
15
79°
59°
16
78°
58°
17
77°
56°
18
75°
54°
19
74°
54°
20
73°
55°
21
74°
55°
22
73°
56°
23
76°
59°
24
79°
60°
25
79°
60°
26
80°
61°
27
80°
61°
28
79°
60°
29
80°
61°
30
79°
60°
31
76°
58°
1
76°
56°
2
77°
56°
3
76°
54°
4
73°
54°
5
73°
54°
6
74°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Rancho San Diego
Rancho San Diego's May 2026 forecast shows daily high temperatures ranging from 67° to 80°, with overnight lows between 48° and 61°. The average high for May is 76° with an average low of 56°. 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 Rancho San Diego. See also: June | July | August.
