S
M
T
W
T
F
S
26
58°
37°
27
65°
40°
28
62°
50°
29
50°
40°
30
54°
39°
1
50°
32°
2
47°
31°
3
58°
32°
4
73°
49°
5
63°
47°
6
49°
39°
7
54°
39°
8
55°
37°
9
62°
42°
10
58°
41°
11
55°
38°
12
55°
36°
13
58°
42°
14
54°
44°
15
64°
48°
16
75°
53°
17
75°
49°
18
68°
59°
19
75°
55°
20
62°
46°
21
59°
50°
22
61°
49°
23
62°
50°
24
58°
48°
25
62°
50°
26
64°
48°
27
64°
51°
28
63°
52°
29
64°
54°
30
70°
51°
31
64°
46°
1
63°
46°
2
62°
47°
3
64°
46°
4
66°
50°
5
69°
56°
6
75°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Thornhill
Thornhill's May 2026 forecast shows daily high temperatures ranging from 54° to 75°, with overnight lows between 42° and 59°. The average high for May is 65° 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 Thornhill. See also: June | July | August.
