S
M
T
W
T
F
S
26
90°
61°
27
92°
61°
28
93°
62°
29
94°
63°
30
95°
64°
31
96°
64°
1
97°
64°
2
97°
64°
3
96°
64°
4
97°
64°
5
96°
63°
6
96°
64°
7
95°
64°
8
96°
63°
9
97°
64°
10
97°
64°
11
98°
63°
12
97°
64°
13
96°
64°
14
96°
64°
15
98°
63°
16
96°
61°
17
97°
62°
18
95°
62°
19
96°
61°
20
95°
62°
21
97°
64°
22
98°
64°
23
99°
63°
24
100°
64°
25
100°
65°
26
99°
64°
27
99°
64°
28
98°
63°
29
98°
62°
30
97°
62°
31
94°
63°
1
97°
62°
2
97°
62°
3
96°
61°
4
94°
58°
5
92°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Simi Valley
Simi Valley's August 2026 forecast shows daily high temperatures ranging from 90° to 100°, with overnight lows between 56° and 65°. The average high for August is 96° with an average low of 63°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how August weather will actually feel in Simi Valley. See also: September | October | November.
