S
M
T
W
T
F
S
26
88°
69°
27
88°
70°
28
85°
69°
29
86°
69°
30
90°
70°
31
91°
70°
1
92°
68°
2
92°
70°
3
89°
69°
4
86°
69°
5
86°
67°
6
88°
68°
7
91°
69°
8
97°
68°
9
95°
70°
10
90°
71°
11
91°
71°
12
87°
70°
13
84°
70°
14
84°
69°
15
88°
69°
16
88°
66°
17
93°
66°
18
92°
68°
19
94°
68°
20
92°
68°
21
93°
70°
22
93°
70°
23
98°
70°
24
97°
72°
25
98°
74°
26
99°
72°
27
99°
74°
28
99°
71°
29
98°
73°
30
93°
71°
31
92°
69°
1
91°
68°
2
91°
71°
3
88°
70°
4
89°
71°
5
89°
66°
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 88° to 99°, with overnight lows between 66° and 74°. The average high for August is 94° 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 Fullerton. See also: September | October | November.
