S
M
T
W
T
F
S
30
77°
59°
31
80°
61°
1
81°
60°
2
81°
58°
3
77°
60°
4
76°
60°
5
80°
59°
6
82°
61°
7
81°
59°
8
81°
60°
9
80°
57°
10
77°
53°
11
76°
54°
12
77°
56°
13
76°
55°
14
75°
54°
15
78°
55°
16
80°
57°
17
78°
61°
18
81°
61°
19
73°
60°
20
74°
60°
21
79°
59°
22
80°
61°
23
78°
60°
24
79°
60°
25
80°
59°
26
80°
60°
27
79°
58°
28
75°
59°
29
75°
59°
30
76°
57°
1
80°
58°
2
81°
59°
3
80°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Los Altos
Los Altos's September 2026 forecast shows daily high temperatures ranging from 73° to 82°, with overnight lows between 53° and 61°. The average high for September is 78° 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 Los Altos. See also: October | November | December.
