S
M
T
W
T
F
S
26
74°
47°
27
69°
49°
28
63°
49°
29
59°
37°
30
61°
38°
1
53°
34°
2
58°
34°
3
69°
47°
4
80°
44°
5
55°
38°
6
57°
35°
7
62°
37°
8
66°
49°
9
76°
41°
10
67°
40°
11
67°
40°
12
76°
49°
13
66°
39°
14
71°
43°
15
75°
54°
16
N/A
17
88°
67°
18
78°
69°
19
78°
49°
20
65°
45°
21
66°
47°
22
72°
53°
23
77°
58°
24
76°
59°
25
74°
56°
26
77°
57°
27
78°
58°
28
77°
56°
29
75°
55°
30
78°
61°
31
80°
60°
1
79°
61°
2
79°
60°
3
72°
56°
4
71°
54°
5
73°
61°
6
78°
63°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
May Weather in Ottawa
Ottawa's May 2026 forecast shows daily high temperatures ranging from 65° to 88°, with overnight lows between 45° and 69°. The average high for May is 76° with an average low of 57°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how May weather will actually feel in Ottawa. See also: June | July | August.
