S
M
T
W
T
F
S
26
90°
61°
27
93°
62°
28
94°
64°
29
95°
65°
30
96°
66°
31
97°
67°
1
96°
68°
2
97°
68°
3
97°
67°
4
96°
67°
5
97°
66°
6
96°
66°
7
96°
67°
8
97°
68°
9
97°
68°
10
96°
67°
11
97°
68°
12
97°
67°
13
96°
64°
14
93°
66°
15
96°
66°
16
96°
64°
17
95°
63°
18
94°
62°
19
93°
63°
20
94°
63°
21
95°
67°
22
98°
69°
23
99°
68°
24
99°
68°
25
100°
69°
26
99°
68°
27
99°
67°
28
98°
66°
29
98°
63°
30
97°
62°
31
94°
63°
1
97°
63°
2
98°
64°
3
97°
62°
4
94°
60°
5
92°
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 100°, with overnight lows between 59° and 69°. The average high for August is 96° with an average low of 65°. 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.
