S
M
T
W
T
F
S
30
86°
67°
31
85°
62°
1
84°
62°
2
84°
61°
3
83°
60°
4
83°
60°
5
84°
62°
6
83°
64°
7
86°
62°
8
86°
62°
9
83°
65°
10
86°
65°
11
87°
66°
12
88°
65°
13
88°
65°
14
86°
64°
15
88°
64°
16
87°
62°
17
88°
63°
18
87°
61°
19
80°
63°
20
85°
61°
21
86°
54°
22
79°
53°
23
77°
54°
24
Hist. Avg.
80°
55°
25
Hist. Avg.
79°
55°
26
Hist. Avg.
79°
55°
27
Hist. Avg.
79°
54°
28
Hist. Avg.
78°
54°
29
Hist. Avg.
78°
54°
30
Hist. Avg.
78°
53°
1
Hist. Avg.
77°
53°
2
Hist. Avg.
77°
52°
3
Hist. Avg.
76°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Mountain View
Mountain View's September 2026 forecast shows daily high temperatures ranging from 77° to 88°, with overnight lows between 53° and 67°. The average high for September is 85° with an average low of 62°. 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.
