S
M
T
W
T
F
S
26
60°
45°
27
57°
44°
28
59°
43°
29
59°
41°
30
57°
40°
1
56°
39°
2
55°
41°
3
54°
38°
4
53°
37°
5
54°
38°
6
54°
37°
7
53°
38°
8
54°
38°
9
54°
39°
10
55°
38°
11
55°
41°
12
56°
43°
13
61°
44°
14
61°
44°
15
58°
41°
16
56°
43°
17
58°
44°
18
57°
42°
19
58°
44°
20
57°
44°
21
57°
43°
22
58°
42°
23
57°
44°
24
58°
45°
25
58°
44°
26
59°
45°
27
58°
46°
28
58°
44°
29
59°
44°
30
60°
46°
31
59°
45°
1
63°
46°
2
64°
46°
3
63°
41°
4
61°
42°
5
64°
44°
6
63°
43°
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 53° to 64°, with overnight lows between 37° and 46°. The average high for May is 58° with an average low of 42°. 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.
