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
76°
55°
16
79°
61°
17
82°
61°
18
74°
63°
19
74°
47°
20
67°
43°
21
68°
49°
22
N/A
23
77°
60°
24
82°
56°
25
88°
60°
26
86°
63°
27
79°
60°
28
80°
56°
29
79°
55°
30
74°
56°
31
77°
57°
1
78°
58°
2
78°
61°
3
80°
60°
4
78°
57°
5
76°
58°
6
73°
55°
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 73° to 88°, with overnight lows between 55° and 63°. The average high for May is 79° with an average low of 58°. 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.
