S
M
T
W
T
F
S
30
77°
55°
31
73°
57°
1
75°
62°
2
78°
59°
3
80°
58°
4
75°
59°
5
79°
54°
6
79°
56°
7
88°
54°
8
92°
59°
9
97°
68°
10
96°
62°
11
83°
58°
12
75°
57°
13
76°
54°
14
80°
57°
15
80°
59°
16
77°
59°
17
78°
59°
18
79°
57°
19
79°
56°
20
77°
57°
21
81°
60°
22
87°
60°
23
90°
67°
24
80°
57°
25
76°
58°
26
81°
60°
27
75°
55°
28
77°
53°
29
78°
56°
30
82°
60°
1
83°
60°
2
82°
59°
3
82°
59°
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 75° to 96°, with overnight lows between 53° and 67°. The average high for September is 81° 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.
