S
M
T
W
T
F
S
29
67°
46°
30
64°
47°
1
66°
40°
2
52°
33°
3
52°
32°
4
57°
39°
5
61°
40°
6
52°
34°
7
51°
33°
8
49°
31°
9
49°
32°
10
48°
31°
11
51°
32°
12
55°
36°
13
57°
34°
14
52°
35°
15
51°
38°
16
50°
40°
17
51°
34°
18
52°
31°
19
49°
29°
20
48°
29°
21
48°
30°
22
50°
33°
23
49°
33°
24
47°
29°
25
47°
28°
26
48°
29°
27
48°
29°
28
49°
30°
29
48°
33°
30
48°
30°
31
49°
29°
1
47°
27°
2
46°
28°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Monticello
Monticello's December 2026 forecast shows daily high temperatures ranging from 46° to 67°, with overnight lows between 27° and 47°. The average high for December is 52° with an average low of 33°. 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.
