S
M
T
W
T
F
S
26
63°
51°
27
71°
43°
28
64°
46°
29
69°
56°
30
73°
50°
1
70°
41°
2
63°
44°
3
67°
32°
4
79°
36°
5
82°
50°
6
73°
63°
7
65°
45°
8
72°
39°
9
77°
43°
10
85°
52°
11
62°
41°
12
74°
40°
13
79°
45°
14
67°
43°
15
76°
39°
16
86°
49°
17
93°
60°
18
95°
62°
19
95°
64°
20
95°
63°
21
93°
58°
22
59°
56°
23
57°
53°
24
74°
63°
25
78°
67°
26
77°
67°
27
82°
64°
28
80°
59°
29
75°
56°
30
73°
53°
31
69°
51°
1
72°
54°
2
77°
55°
3
75°
57°
4
77°
56°
5
81°
57°
6
75°
53°
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 69° to 82°, with overnight lows between 51° and 67°. The average high for May is 76° 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 Markham. See also: June | July | August.
