S
M
T
W
T
F
S
26
62°
55°
27
63°
52°
28
66°
52°
29
66°
52°
30
66°
52°
1
63°
54°
2
61°
54°
3
65°
54°
4
64°
53°
5
65°
53°
6
67°
54°
7
62°
53°
8
60°
53°
9
64°
53°
10
64°
53°
11
72°
50°
12
62°
51°
13
65°
53°
14
66°
51°
15
66°
51°
16
66°
52°
17
73°
50°
18
80°
56°
19
82°
54°
20
73°
53°
21
70°
51°
22
69°
50°
23
69°
54°
24
71°
55°
25
66°
55°
26
64°
53°
27
66°
54°
28
68°
53°
29
64°
51°
30
65°
52°
31
67°
52°
1
70°
52°
2
67°
55°
3
70°
56°
4
69°
55°
5
68°
53°
6
67°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in South San Francisco
South San Francisco's May 2026 forecast shows daily high temperatures ranging from 64° to 70°, with overnight lows between 51° and 56°. The average high for May is 67° with an average low of 53°. 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 South San Francisco. See also: June | July | August.
