S
M
T
W
T
F
S
26
97°
67°
27
96°
67°
28
96°
65°
29
92°
64°
30
97°
63°
31
101°
64°
1
104°
68°
2
102°
64°
3
99°
62°
4
99°
65°
5
98°
66°
6
99°
71°
7
100°
69°
8
98°
68°
9
97°
67°
10
97°
67°
11
95°
67°
12
93°
68°
13
97°
66°
14
96°
65°
15
92°
68°
16
94°
67°
17
91°
67°
18
93°
67°
19
94°
68°
20
95°
68°
21
96°
67°
22
97°
68°
23
97°
69°
24
98°
69°
25
97°
68°
26
97°
69°
27
96°
68°
28
97°
69°
29
96°
68°
30
97°
69°
31
97°
69°
1
95°
68°
2
96°
68°
3
93°
67°
4
93°
68°
5
94°
68°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Castaic
Castaic's August 2026 forecast shows daily high temperatures ranging from 91° to 104°, with overnight lows between 62° and 71°. The average high for August is 96° with an average low of 68°. 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 Castaic. See also: September | October | November.
