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
75°
59°
17
79°
57°
18
81°
56°
19
79°
55°
20
76°
55°
21
77°
59°
22
80°
57°
23
81°
61°
24
80°
60°
25
77°
60°
26
77°
59°
27
78°
60°
28
78°
59°
29
77°
56°
30
74°
56°
1
79°
58°
2
73°
58°
3
79°
55°
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 73° to 81°, with overnight lows between 55° and 61°. The average high for September is 78° 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 Mountain View. See also: October | November | December.
