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°
64°
11
81°
61°
12
79°
60°
13
75°
59°
14
85°
55°
15
79°
55°
16
74°
58°
17
75°
61°
18
77°
58°
19
77°
58°
20
68°
58°
21
76°
58°
22
75°
57°
23
84°
54°
24
88°
61°
25
78°
60°
26
77°
52°
27
74°
55°
28
76°
51°
29
86°
57°
30
87°
57°
1
85°
60°
2
87°
62°
3
92°
62°
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 85° to 92°, with overnight lows between 57° and 62°. The average high for September is 87° with an average low of 60°. 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.
