S
M
T
W
T
F
S
30
79°
66°
31
75°
62°
1
80°
62°
2
79°
63°
3
77°
64°
4
77°
64°
5
80°
70°
6
83°
67°
7
87°
66°
8
85°
65°
9
83°
63°
10
82°
63°
11
84°
65°
12
83°
63°
13
84°
64°
14
83°
60°
15
86°
65°
16
86°
64°
17
85°
63°
18
83°
60°
19
79°
59°
20
81°
60°
21
84°
61°
22
85°
62°
23
84°
61°
24
81°
58°
25
77°
55°
26
77°
55°
27
76°
54°
28
77°
55°
29
79°
56°
30
79°
58°
1
78°
56°
2
80°
58°
3
84°
61°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Aliso Viejo
Aliso Viejo's September 2026 forecast shows daily high temperatures ranging from 76° to 87°, with overnight lows between 54° and 70°. The average high for September is 81° with an average low of 61°. 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 Aliso Viejo. See also: October | November | December.
