S
M
T
W
T
F
S
26
63°
54°
27
63°
52°
28
67°
51°
29
65°
50°
30
67°
51°
1
66°
53°
2
59°
54°
3
66°
53°
4
66°
54°
5
65°
55°
6
70°
55°
7
70°
53°
8
68°
56°
9
73°
55°
10
72°
56°
11
71°
55°
12
79°
55°
13
77°
56°
14
73°
53°
15
69°
55°
16
68°
51°
17
72°
54°
18
72°
55°
19
71°
55°
20
73°
54°
21
72°
54°
22
71°
53°
23
73°
55°
24
74°
55°
25
74°
54°
26
73°
54°
27
67°
53°
28
66°
53°
29
67°
54°
30
67°
54°
31
68°
56°
1
70°
56°
2
73°
55°
3
72°
55°
4
67°
54°
5
68°
54°
6
66°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in San Mateo
San Mateo's May 2026 forecast shows daily high temperatures ranging from 65° to 79°, with overnight lows between 51° and 56°. The average high for May is 70° with an average low of 54°. 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 San Mateo. See also: June | July | August.
