S
M
T
W
T
F
S
26
91°
66°
27
88°
64°
28
86°
64°
29
84°
64°
30
88°
61°
31
90°
64°
1
88°
64°
2
93°
66°
3
88°
66°
4
86°
64°
5
84°
63°
6
86°
64°
7
91°
64°
8
90°
63°
9
91°
64°
10
90°
66°
11
90°
66°
12
84°
66°
13
81°
64°
14
82°
64°
15
84°
63°
16
84°
63°
17
87°
61°
18
87°
63°
19
90°
64°
20
90°
65°
21
91°
65°
22
90°
64°
23
89°
63°
24
88°
64°
25
90°
62°
26
88°
64°
27
89°
65°
28
88°
61°
29
85°
64°
30
86°
64°
31
83°
64°
1
83°
64°
2
84°
63°
3
84°
65°
4
86°
65°
5
88°
64°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Fallbrook
Fallbrook's August 2026 forecast shows daily high temperatures ranging from 83° to 91°, with overnight lows between 61° and 65°. The average high for August is 87° with an average low of 64°. 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 Fallbrook. See also: September | October | November.
