S
M
T
W
T
F
S
30
84°
69°
31
90°
66°
1
93°
70°
2
94°
73°
3
95°
73°
4
95°
71°
5
92°
73°
6
82°
68°
7
81°
64°
8
82°
63°
9
89°
67°
10
89°
70°
11
85°
66°
12
79°
67°
13
87°
68°
14
89°
64°
15
89°
65°
16
87°
66°
17
83°
67°
18
84°
60°
19
75°
64°
20
75°
63°
21
83°
65°
22
82°
64°
23
81°
63°
24
80°
63°
25
81°
62°
26
82°
63°
27
82°
63°
28
81°
62°
29
81°
62°
30
80°
61°
1
79°
62°
2
79°
60°
3
78°
58°
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 75° to 89°, with overnight lows between 58° and 70°. The average high for September is 82° with an average low of 64°. 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.
