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°
60°
24
87°
62°
25
80°
56°
26
78°
56°
27
75°
56°
28
77°
56°
29
83°
57°
30
80°
58°
1
77°
56°
2
74°
52°
3
81°
55°
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 74° to 87°, with overnight lows between 52° and 62°. The average high for September is 79° with an average low of 57°. 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.
