S
M
T
W
T
F
S
29
37°
21°
30
35°
26°
1
43°
20°
2
39°
23°
3
37°
21°
4
49°
17°
5
47°
18°
6
31°
17°
7
33°
20°
8
34°
16°
9
33°
14°
10
31°
14°
11
28°
16°
12
28°
16°
13
30°
17°
14
30°
16°
15
31°
21°
16
31°
21°
17
32°
17°
18
32°
25°
19
34°
24°
20
35°
19°
21
33°
18°
22
29°
14°
23
29°
12°
24
30°
17°
25
28°
17°
26
29°
18°
27
27°
18°
28
30°
17°
29
30°
14°
30
30°
11°
31
Hist. Avg.
32°
16°
1
Hist. Avg.
31°
16°
2
Hist. Avg.
31°
15°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
December Weather in Monticello
Monticello's December 2026 forecast shows daily high temperatures ranging from 27° to 49°, with overnight lows between 11° and 26°. The average high for December is 33° with an average low of 18°. 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 Monticello. See also: January | February | March.
