S
M
T
W
T
F
S
26
86°
56°
27
86°
64°
28
80°
63°
29
82°
63°
30
81°
66°
31
87°
61°
1
87°
62°
2
84°
73°
3
85°
64°
4
85°
56°
5
84°
66°
6
91°
73°
7
92°
69°
8
86°
68°
9
89°
68°
10
85°
64°
11
84°
68°
12
86°
68°
13
88°
64°
14
85°
64°
15
85°
65°
16
81°
70°
17
87°
65°
18
84°
63°
19
85°
62°
20
86°
64°
21
86°
67°
22
88°
65°
23
83°
62°
24
83°
60°
25
81°
62°
26
85°
63°
27
86°
65°
28
78°
57°
29
78°
57°
30
83°
64°
31
85°
64°
1
85°
63°
2
84°
64°
3
86°
64°
4
85°
63°
5
84°
63°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Fullerton
Fullerton's August 2026 forecast shows daily high temperatures ranging from 78° to 88°, with overnight lows between 57° and 70°. The average high for August is 84° 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 Fullerton. See also: September | October | November.
