S
M
T
W
T
F
S
26
53°
45°
27
70°
39°
28
67°
51°
29
64°
51°
30
65°
40°
1
68°
38°
2
59°
43°
3
63°
38°
4
76°
44°
5
82°
58°
6
74°
57°
7
68°
53°
8
73°
42°
9
73°
53°
10
80°
50°
11
64°
46°
12
73°
37°
13
72°
54°
14
61°
50°
15
74°
52°
16
84°
45°
17
88°
57°
18
94°
60°
19
94°
67°
20
91°
65°
21
68°
52°
22
57°
49°
23
54°
51°
24
67°
60°
25
76°
62°
26
71°
65°
27
75°
64°
28
81°
57°
29
80°
54°
30
76°
52°
31
73°
54°
1
75°
55°
2
76°
56°
3
78°
57°
4
76°
57°
5
80°
58°
6
74°
54°
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 81°, with overnight lows between 51° and 65°. The average high for May is 74° 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 Markham. See also: June | July | August.
