S
M
T
W
T
F
S
26
66°
36°
27
70°
39°
28
59°
43°
29
66°
41°
30
72°
50°
1
75°
50°
2
70°
43°
3
64°
52°
4
59°
48°
5
61°
43°
6
59°
37°
7
63°
36°
8
64°
45°
9
68°
43°
10
57°
30°
11
55°
27°
12
61°
30°
13
55°
39°
14
57°
36°
15
57°
32°
16
57°
32°
17
61°
41°
18
56°
49°
19
62°
50°
20
66°
50°
21
72°
51°
22
79°
58°
23
78°
54°
24
77°
51°
25
74°
52°
26
72°
51°
27
73°
52°
28
72°
51°
29
70°
51°
30
71°
50°
31
60°
47°
1
59°
44°
2
60°
45°
3
63°
50°
4
63°
51°
5
66°
52°
6
67°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Thornton
Thornton's May 2026 forecast shows daily high temperatures ranging from 56° to 79°, with overnight lows between 44° and 58°. The average high for May is 68° with an average low of 51°. 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 Thornton. See also: June | July | August.
