S
M
T
W
T
F
S
30
96°
59°
31
98°
62°
1
98°
74°
2
97°
70°
3
97°
69°
4
98°
72°
5
102°
70°
6
96°
64°
7
93°
62°
8
97°
69°
9
100°
71°
10
89°
68°
11
86°
66°
12
87°
67°
13
92°
68°
14
89°
63°
15
91°
65°
16
87°
65°
17
87°
64°
18
79°
55°
19
79°
60°
20
83°
59°
21
84°
60°
22
83°
60°
23
83°
59°
24
82°
60°
25
83°
61°
26
82°
60°
27
82°
59°
28
81°
60°
29
82°
60°
30
79°
57°
1
77°
52°
2
68°
47°
3
68°
45°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Mountain View
Mountain View's September 2026 forecast shows daily high temperatures ranging from 68° to 102°, with overnight lows between 45° and 71°. The average high for September is 85° with an average low of 61°. 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 Mountain View. See also: October | November | December.
