S
M
T
W
T
F
S
30
97°
72°
31
95°
72°
1
97°
72°
2
97°
72°
3
93°
72°
4
99°
73°
5
93°
72°
6
97°
70°
7
99°
72°
8
97°
75°
9
94°
73°
10
94°
72°
11
101°
73°
12
99°
73°
13
96°
73°
14
99°
73°
15
97°
71°
16
98°
72°
17
96°
73°
18
95°
72°
19
92°
76°
20
91°
76°
21
92°
77°
22
89°
76°
23
91°
75°
24
89°
75°
25
90°
76°
26
90°
76°
27
89°
75°
28
90°
76°
29
90°
76°
30
89°
75°
1
89°
76°
2
88°
76°
3
89°
75°
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 88° to 101°, with overnight lows between 71° and 77°. The average high for September is 93° with an average low of 74°. 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.
