S
M
T
W
T
F
S
26
61°
38°
27
56°
38°
28
59°
45°
29
59°
43°
30
60°
42°
1
63°
47°
2
66°
50°
3
62°
51°
4
69°
52°
5
72°
52°
6
72°
51°
7
67°
47°
8
71°
51°
9
72°
53°
10
71°
53°
11
74°
55°
12
74°
54°
13
73°
49°
14
64°
48°
15
69°
48°
16
68°
47°
17
67°
47°
18
70°
48°
19
71°
52°
20
72°
55°
21
70°
51°
22
69°
46°
23
69°
47°
24
68°
48°
25
70°
48°
26
70°
50°
27
71°
52°
28
74°
59°
29
75°
59°
30
76°
60°
31
78°
54°
1
76°
52°
2
72°
51°
3
71°
52°
4
75°
58°
5
78°
62°
6
81°
63°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Ottawa
Ottawa's May 2026 forecast shows daily high temperatures ranging from 56° to 81°, with overnight lows between 38° and 63°. The average high for May is 70° with an average low of 51°. 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.
