S
M
T
W
T
F
S
26
93°
66°
27
96°
66°
28
95°
61°
29
95°
69°
30
95°
61°
31
100°
65°
1
100°
69°
2
87°
58°
3
87°
58°
4
90°
55°
5
94°
56°
6
99°
63°
7
99°
62°
8
99°
64°
9
95°
63°
10
96°
62°
11
96°
63°
12
97°
63°
13
95°
64°
14
96°
63°
15
101°
61°
16
90°
63°
17
93°
63°
18
95°
63°
19
95°
64°
20
94°
62°
21
92°
61°
22
93°
61°
23
93°
60°
24
91°
60°
25
88°
59°
26
92°
60°
27
93°
62°
28
93°
62°
29
92°
61°
30
91°
60°
31
90°
59°
1
86°
56°
2
79°
54°
3
83°
57°
4
90°
58°
5
90°
57°
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 79° to 101°, with overnight lows between 54° and 64°. The average high for August is 92° with an average low of 60°. 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.
