S
M
T
W
T
F
S
26
93°
66°
27
94°
67°
28
94°
67°
29
93°
66°
30
94°
67°
31
94°
67°
1
93°
66°
2
94°
67°
3
94°
67°
4
93°
66°
5
93°
65°
6
94°
66°
7
94°
66°
8
95°
67°
9
95°
67°
10
94°
66°
11
94°
66°
12
93°
65°
13
93°
66°
14
94°
66°
15
94°
65°
16
93°
66°
17
93°
65°
18
92°
65°
19
94°
64°
20
93°
65°
21
96°
66°
22
95°
66°
23
94°
65°
24
95°
60°
25
94°
59°
26
90°
60°
27
90°
62°
28
89°
63°
29
89°
65°
30
90°
65°
31
92°
64°
1
93°
62°
2
88°
58°
3
87°
59°
4
88°
62°
5
88°
61°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Ontario
Ontario's August 2026 forecast shows daily high temperatures ranging from 87° to 96°, with overnight lows between 58° and 67°. The average high for August is 93° 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 Ontario. See also: September | October | November.
