S
M
T
W
T
F
S
26
62°
33°
27
66°
36°
28
61°
47°
29
48°
36°
30
46°
35°
1
46°
30°
2
47°
27°
3
55°
45°
4
65°
51°
5
59°
38°
6
52°
33°
7
49°
33°
8
47°
34°
9
50°
38°
10
55°
38°
11
54°
38°
12
56°
41°
13
55°
42°
14
56°
39°
15
59°
39°
16
58°
41°
17
59°
44°
18
61°
49°
19
66°
49°
20
67°
48°
21
68°
50°
22
65°
45°
23
62°
48°
24
66°
42°
25
61°
42°
26
63°
50°
27
63°
52°
28
72°
51°
29
66°
49°
30
65°
47°
31
65°
43°
1
63°
45°
2
62°
44°
3
64°
46°
4
64°
45°
5
65°
48°
6
65°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Alliston
Alliston's May 2026 forecast shows daily high temperatures ranging from 46° to 72°, with overnight lows between 27° and 52°. The average high for May is 60° with an average low of 43°. 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 Alliston. See also: June | July | August.
