S
M
T
W
T
F
S
26
96°
68°
27
98°
67°
28
98°
66°
29
94°
66°
30
96°
65°
31
98°
67°
1
97°
66°
2
98°
67°
3
98°
67°
4
97°
68°
5
99°
68°
6
98°
67°
7
98°
67°
8
97°
66°
9
98°
67°
10
98°
66°
11
92°
66°
12
94°
65°
13
95°
63°
14
93°
65°
15
92°
66°
16
95°
66°
17
98°
65°
18
96°
67°
19
97°
66°
20
98°
67°
21
93°
66°
22
92°
67°
23
93°
67°
24
93°
66°
25
94°
65°
26
92°
63°
27
91°
62°
28
91°
67°
29
92°
67°
30
92°
66°
31
95°
66°
1
93°
65°
2
93°
64°
3
94°
64°
4
92°
61°
5
92°
61°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Castaic Junction
Castaic Junction's August 2026 forecast shows daily high temperatures ranging from 91° to 99°, with overnight lows between 61° and 68°. The average high for August is 95° 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 Castaic Junction. See also: September | October | November.
