S
M
T
W
T
F
S
26
90°
61°
27
91°
62°
28
92°
63°
29
92°
63°
30
93°
64°
31
95°
66°
1
96°
67°
2
97°
68°
3
96°
67°
4
95°
65°
5
95°
64°
6
94°
64°
7
95°
65°
8
96°
66°
9
95°
67°
10
95°
65°
11
95°
61°
12
94°
61°
13
93°
63°
14
94°
67°
15
93°
68°
16
96°
67°
17
98°
67°
18
99°
68°
19
96°
67°
20
98°
67°
21
99°
66°
22
99°
67°
23
98°
66°
24
98°
66°
25
96°
67°
26
96°
66°
27
97°
66°
28
96°
63°
29
94°
62°
30
93°
64°
31
93°
61°
1
94°
61°
2
95°
60°
3
92°
59°
4
90°
60°
5
90°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Fontana
Fontana's August 2026 forecast shows daily high temperatures ranging from 90° to 99°, with overnight lows between 59° and 68°. The average high for August is 95° 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 Fontana. See also: September | October | November.
