S
M
T
W
T
F
S
30
82°
58°
31
83°
58°
1
82°
55°
2
81°
57°
3
81°
59°
4
82°
54°
5
78°
54°
6
79°
53°
7
78°
55°
8
79°
56°
9
80°
57°
10
79°
52°
11
78°
53°
12
76°
52°
13
76°
55°
14
Hist. Avg.
79°
53°
15
Hist. Avg.
79°
53°
16
Hist. Avg.
79°
53°
17
Hist. Avg.
78°
52°
18
Hist. Avg.
78°
52°
19
Hist. Avg.
77°
51°
20
Hist. Avg.
77°
51°
21
Hist. Avg.
76°
50°
22
Hist. Avg.
76°
50°
23
Hist. Avg.
76°
50°
24
Hist. Avg.
75°
49°
25
Hist. Avg.
75°
49°
26
Hist. Avg.
74°
48°
27
Hist. Avg.
74°
48°
28
Hist. Avg.
73°
47°
29
Hist. Avg.
73°
47°
30
Hist. Avg.
72°
46°
1
Hist. Avg.
72°
46°
2
Hist. Avg.
71°
46°
3
Hist. Avg.
71°
45°
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 76° to 83°, with overnight lows between 52° and 59°. The average high for September is 80° with an average low of 55°. 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.
