S
M
T
W
T
F
S
30
72°
55°
31
70°
57°
1
73°
61°
2
77°
59°
3
79°
57°
4
72°
59°
5
75°
55°
6
75°
55°
7
86°
54°
8
88°
59°
9
97°
68°
10
90°
64°
11
75°
63°
12
77°
61°
13
73°
59°
14
81°
55°
15
72°
57°
16
72°
57°
17
72°
59°
18
73°
55°
19
72°
59°
20
64°
59°
21
70°
59°
22
68°
57°
23
79°
57°
24
82°
61°
25
73°
59°
26
72°
52°
27
68°
55°
28
72°
52°
29
81°
54°
30
81°
57°
1
77°
57°
2
79°
61°
3
91°
61°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Cupertino
Cupertino's September 2026 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for September is ° with an average low of °. 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 Cupertino. See also: October | November | December.
