S
M
T
W
T
F
S
26
52°
37°
27
52°
36°
28
57°
36°
29
54°
41°
30
43°
36°
1
50°
35°
2
65°
43°
3
70°
46°
4
63°
44°
5
63°
45°
6
62°
44°
7
59°
41°
8
62°
45°
9
64°
47°
10
65°
48°
11
70°
42°
12
63°
40°
13
61°
39°
14
64°
38°
15
70°
42°
16
75°
46°
17
76°
49°
18
77°
49°
19
76°
50°
20
77°
50°
21
77°
49°
22
76°
49°
23
76°
50°
24
72°
51°
25
72°
50°
26
78°
52°
27
80°
52°
28
81°
53°
29
80°
54°
30
76°
53°
31
82°
54°
1
81°
54°
2
81°
55°
3
73°
55°
4
75°
54°
5
75°
49°
6
77°
50°
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 43° to 82°, with overnight lows between 35° and 55°. The average high for May is 70° with an average low of 47°. 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.
