S
M
T
W
T
F
S
30
85°
60°
31
84°
63°
1
85°
64°
2
84°
62°
3
86°
63°
4
89°
65°
5
90°
64°
6
89°
65°
7
88°
66°
8
89°
64°
9
89°
61°
10
87°
62°
11
82°
62°
12
80°
60°
13
82°
60°
14
85°
58°
15
79°
58°
16
79°
56°
17
82°
57°
18
82°
61°
19
79°
61°
20
80°
57°
21
79°
56°
22
78°
53°
23
77°
55°
24
81°
54°
25
78°
55°
26
82°
57°
27
81°
54°
28
80°
54°
29
81°
53°
30
83°
52°
1
81°
48°
2
72°
48°
3
76°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in San Jose
San Jose's September 2026 forecast shows daily high temperatures ranging from 72° to 90°, with overnight lows between 48° and 66°. The average high for September is 82° with an average low of 58°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in San Jose. See also: October | November | December.
