S
M
T
W
T
F
S
26
84°
64°
27
84°
61°
28
74°
65°
29
75°
66°
30
82°
63°
31
85°
60°
1
79°
63°
2
73°
67°
3
78°
59°
4
84°
56°
5
86°
65°
6
83°
67°
7
85°
67°
8
83°
64°
9
80°
61°
10
78°
61°
11
78°
60°
12
77°
59°
13
76°
57°
14
74°
56°
15
76°
58°
16
76°
57°
17
75°
61°
18
73°
60°
19
71°
57°
20
77°
54°
21
71°
55°
22
75°
60°
23
78°
60°
24
75°
59°
25
76°
58°
26
77°
60°
27
75°
59°
28
74°
60°
29
76°
58°
30
77°
59°
31
78°
56°
1
70°
54°
2
67°
54°
3
68°
52°
4
70°
53°
5
73°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Ottawa
Ottawa's August 2026 forecast shows daily high temperatures ranging from 67° to 86°, with overnight lows between 52° and 67°. The average high for August is 76° with an average low of 59°. 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 Ottawa. See also: September | October | November.
