S
M
T
W
T
F
S
29
67°
43°
30
65°
45°
31
60°
42°
1
56°
39°
2
43°
31°
3
50°
30°
4
57°
28°
5
64°
28°
6
68°
32°
7
69°
36°
8
66°
38°
9
68°
39°
10
73°
46°
11
69°
45°
12
58°
38°
13
53°
38°
14
60°
37°
15
63°
39°
16
54°
36°
17
57°
38°
18
56°
38°
19
55°
35°
20
65°
44°
21
49°
27°
22
51°
32°
23
51°
28°
24
52°
30°
25
54°
35°
26
55°
31°
27
60°
32°
28
63°
36°
29
64°
39°
30
64°
39°
1
65°
40°
2
65°
40°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
April Weather in Thornton
Thornton's April 2026 forecast shows daily high temperatures ranging from 49° to 73°, with overnight lows between 27° and 46°. The average high for April is 60° with an average low of 37°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how April weather will actually feel in Thornton. See also: May | June | July.