S
M
T
W
T
F
S
26
94°
64°
27
90°
65°
28
89°
63°
29
85°
64°
30
88°
60°
31
92°
59°
1
94°
63°
2
90°
64°
3
89°
62°
4
85°
59°
5
85°
58°
6
91°
62°
7
93°
64°
8
94°
65°
9
93°
67°
10
91°
67°
11
87°
66°
12
85°
64°
13
83°
62°
14
82°
61°
15
83°
59°
16
86°
59°
17
89°
60°
18
91°
64°
19
93°
64°
20
90°
64°
21
N/A
22
97°
67°
23
99°
66°
24
100°
68°
25
100°
71°
26
105°
67°
27
104°
66°
28
103°
67°
29
102°
66°
30
102°
65°
31
99°
64°
1
98°
65°
2
98°
64°
3
99°
65°
4
91°
62°
5
95°
63°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
August Weather in Simi Valley
Simi Valley's August 2026 forecast shows daily high temperatures ranging from 91° to 105°, with overnight lows between 62° and 71°. The average high for August is 99° with an average low of 66°. 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.
