S
M
T
W
T
F
S
26
48°
38°
27
53°
31°
28
66°
29°
29
70°
33°
30
73°
40°
1
76°
41°
2
80°
46°
3
69°
46°
4
50°
38°
5
48°
38°
6
67°
33°
7
78°
42°
8
81°
45°
9
83°
44°
10
90°
47°
11
87°
48°
12
87°
55°
13
81°
44°
14
75°
44°
15
76°
46°
16
67°
42°
17
60°
40°
18
66°
51°
19
69°
41°
20
73°
39°
21
73°
69°
22
78°
47°
23
79°
45°
24
77°
47°
25
75°
43°
26
64°
39°
27
57°
37°
28
47°
40°
29
51°
44°
30
58°
47°
31
57°
50°
1
57°
49°
2
77°
42°
3
77°
42°
4
80°
43°
5
71°
42°
6
69°
42°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Mount San Jacinto State Park
Mount San Jacinto State Park's May 2026 forecast shows daily high temperatures ranging from 47° to 80°, with overnight lows between 40° and 50°. The average high for May is 64° with an average low of 44°. 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 Mount San Jacinto State Park. See also: June | July | August.
