S
M
T
W
T
F
S
30
89°
66°
31
84°
57°
1
82°
54°
2
79°
54°
3
81°
56°
4
81°
57°
5
88°
57°
6
72°
64°
7
90°
65°
8
87°
68°
9
105°
71°
10
99°
74°
11
91°
71°
12
87°
66°
13
84°
62°
14
83°
59°
15
82°
64°
16
77°
64°
17
77°
58°
18
77°
54°
19
80°
56°
20
80°
58°
21
76°
59°
22
N/A
23
N/A
24
N/A
25
85°
58°
26
90°
62°
27
88°
62°
28
80°
56°
29
88°
59°
30
88°
60°
1
87°
57°
2
100°
62°
3
101°
69°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Simi Valley
Simi Valley's September 2026 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for September is ° with an average low of °. 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 Simi Valley. See also: October | November | December.
