S
M
T
W
T
F
S
26
N/A
27
N/A
28
N/A
29
N/A
30
N/A
1
N/A
2
N/A
3
N/A
4
N/A
5
N/A
6
N/A
7
N/A
8
N/A
9
N/A
10
N/A
11
N/A
12
N/A
13
N/A
14
N/A
15
N/A
16
N/A
17
N/A
18
N/A
19
N/A
20
N/A
21
N/A
22
N/A
23
N/A
24
62°
53°
25
75°
49°
26
82°
52°
27
82°
54°
28
72°
47°
29
65°
42°
30
65°
41°
31
65°
44°
1
69°
46°
2
66°
46°
3
72°
51°
4
72°
52°
5
71°
51°
6
72°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Riverside
Riverside's May 2026 forecast shows daily high temperatures ranging from 62° to 82°, with overnight lows between 41° and 54°. The average high for May is 71° with an average low of 48°. 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 Riverside. See also: June | July | August.