S
M
T
W
T
F
S
30
87°
63°
31
88°
65°
1
87°
64°
2
88°
64°
3
88°
63°
4
87°
64°
5
87°
64°
6
86°
63°
7
86°
62°
8
79°
62°
9
80°
61°
10
79°
62°
11
85°
61°
12
84°
62°
13
86°
62°
14
85°
61°
15
84°
60°
16
77°
57°
17
78°
52°
18
76°
56°
19
80°
51°
20
76°
51°
21
74°
52°
22
73°
52°
23
75°
56°
24
81°
57°
25
81°
57°
26
80°
56°
27
81°
55°
28
79°
53°
29
78°
52°
30
79°
52°
1
76°
51°
2
79°
53°
3
72°
46°
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 72° to 88°, with overnight lows between 46° and 65°. The average high for September is 81° 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.
