S
M
T
W
T
F
S
26
65°
40°
27
67°
52°
28
63°
50°
29
56°
36°
30
56°
33°
1
49°
33°
2
57°
40°
3
61°
47°
4
74°
50°
5
55°
41°
6
55°
39°
7
54°
39°
8
58°
42°
9
60°
43°
10
61°
45°
11
65°
47°
12
64°
49°
13
65°
52°
14
67°
50°
15
70°
49°
16
71°
56°
17
73°
53°
18
66°
52°
19
72°
56°
20
71°
55°
21
69°
46°
22
65°
46°
23
65°
47°
24
67°
47°
25
67°
48°
26
68°
48°
27
67°
49°
28
68°
48°
29
69°
53°
30
70°
59°
31
75°
54°
1
70°
54°
2
74°
59°
3
76°
59°
4
79°
60°
5
79°
61°
6
80°
62°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Markham
Markham's May 2026 forecast shows daily high temperatures ranging from 54° to 80°, with overnight lows between 39° and 62°. The average high for May is 67° with an average low of 50°. 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 Markham. See also: June | July | August.
