S
M
T
W
T
F
S
30
90°
66°
31
86°
62°
1
84°
61°
2
84°
61°
3
85°
65°
4
88°
67°
5
89°
64°
6
87°
64°
7
89°
65°
8
86°
64°
9
83°
59°
10
83°
62°
11
85°
58°
12
82°
57°
13
81°
58°
14
80°
57°
15
81°
58°
16
81°
57°
17
84°
59°
18
85°
59°
19
85°
62°
20
83°
55°
21
78°
55°
22
78°
53°
23
Hist. Avg.
80°
56°
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 78° to 90°, with overnight lows between 53° and 67°. The average high for September is 84° with an average low of 60°. 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.
