S
M
T
W
T
F
S
26
80°
68°
27
80°
69°
28
78°
69°
29
80°
69°
30
79°
69°
31
79°
68°
1
80°
68°
2
80°
68°
3
78°
67°
4
79°
67°
5
78°
66°
6
79°
65°
7
79°
67°
8
78°
65°
9
80°
66°
10
79°
68°
11
79°
67°
12
79°
66°
13
79°
68°
14
79°
68°
15
77°
67°
16
77°
65°
17
77°
64°
18
78°
67°
19
79°
65°
20
79°
67°
21
81°
67°
22
80°
67°
23
91°
67°
24
82°
68°
25
90°
72°
26
89°
74°
27
88°
74°
28
92°
74°
29
89°
70°
30
83°
70°
31
80°
68°
1
84°
69°
2
86°
70°
3
84°
70°
4
82°
68°
5
83°
69°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Fountain Valley
Fountain Valley's August 2026 forecast shows daily high temperatures ranging from 80° to 92°, with overnight lows between 68° and 74°. The average high for August is 86° with an average low of 71°. 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 Fountain Valley. See also: September | October | November.
