S
M
T
W
T
F
S
26
84°
71°
27
86°
73°
28
83°
72°
29
73°
59°
30
63°
57°
1
57°
51°
2
74°
48°
3
78°
50°
4
80°
54°
5
83°
68°
6
73°
55°
7
67°
52°
8
76°
56°
9
88°
69°
10
84°
62°
11
77°
60°
12
81°
56°
13
86°
59°
14
88°
62°
15
83°
66°
16
86°
69°
17
85°
72°
18
88°
75°
19
84°
65°
20
79°
68°
21
77°
66°
22
84°
70°
23
79°
65°
24
78°
65°
25
83°
67°
26
85°
69°
27
83°
70°
28
82°
68°
29
83°
69°
30
86°
68°
31
85°
69°
1
87°
67°
2
86°
69°
3
85°
67°
4
84°
64°
5
84°
66°
6
85°
71°
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 77° to 87°, with overnight lows between 64° and 71°. The average high for May is 83° with an average low of 68°. 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.
