S
M
T
W
T
F
S
29
48°
29°
30
45°
24°
1
38°
20°
2
32°
15°
3
37°
27°
4
41°
25°
5
36°
26°
6
34°
19°
7
31°
15°
8
30°
16°
9
35°
18°
10
38°
25°
11
39°
24°
12
43°
23°
13
40°
25°
14
35°
23°
15
37°
20°
16
38°
20°
17
36°
16°
18
33°
13°
19
32°
8°
20
28°
7°
21
26°
20°
22
35°
16°
23
36°
15°
24
34°
7°
25
30°
12°
26
28°
20°
27
35°
18°
28
36°
15°
29
32°
9°
30
31°
15°
31
29°
5°
1
32°
1°
2
25°
7°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Diagonal
Diagonal's December 2026 forecast shows daily high temperatures ranging from 25° to 48°, with overnight lows between 1° and 29°. The average high for December is 35° with an average low of 17°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how December weather will actually feel in Diagonal. See also: January | February | March.
