S
M
T
W
T
F
S
30
79°
67°
31
80°
67°
1
80°
66°
2
79°
66°
3
79°
65°
4
78°
67°
5
80°
67°
6
79°
66°
7
80°
66°
8
79°
65°
9
80°
67°
10
81°
67°
11
81°
66°
12
80°
67°
13
81°
66°
14
81°
66°
15
80°
65°
16
79°
62°
17
79°
66°
18
78°
66°
19
80°
65°
20
80°
66°
21
79°
66°
22
78°
65°
23
79°
66°
24
78°
65°
25
79°
66°
26
78°
65°
27
80°
66°
28
79°
65°
29
79°
65°
30
79°
65°
1
79°
65°
2
79°
66°
3
Hist. Avg.
83°
69°
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 78° to 81°, with overnight lows between 62° and 67°. The average high for September is 79° with an average low of 66°. 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.
