S
M
T
W
T
F
S
26
82°
63°
27
82°
60°
28
79°
57°
29
75°
60°
30
80°
61°
31
75°
55°
1
78°
54°
2
75°
55°
3
73°
53°
4
74°
54°
5
75°
54°
6
75°
53°
7
76°
54°
8
80°
56°
9
75°
62°
10
77°
58°
11
78°
61°
12
83°
61°
13
82°
62°
14
82°
55°
15
77°
51°
16
74°
58°
17
75°
50°
18
73°
51°
19
72°
52°
20
74°
53°
21
76°
54°
22
73°
52°
23
71°
55°
24
75°
58°
25
72°
50°
26
74°
59°
27
78°
52°
28
79°
52°
29
70°
55°
30
69°
49°
31
69°
50°
1
70°
48°
2
69°
53°
3
69°
55°
4
73°
48°
5
70°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Old Ottawa
Old Ottawa's August 2026 forecast shows daily high temperatures ranging from 69° to 83°, with overnight lows between 47° and 63°. The average high for August is 75° with an average low of 55°. 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 Old Ottawa. See also: September | October | November.
