S
M
T
W
T
F
S
29
73°
47°
30
70°
48°
1
72°
44°
2
60°
37°
3
59°
34°
4
60°
38°
5
65°
43°
6
60°
37°
7
58°
37°
8
56°
34°
9
56°
35°
10
55°
33°
11
56°
33°
12
58°
34°
13
63°
35°
14
60°
37°
15
61°
44°
16
62°
38°
17
63°
37°
18
66°
35°
19
59°
30°
20
56°
30°
21
56°
31°
22
58°
33°
23
58°
33°
24
55°
31°
25
56°
30°
26
55°
31°
27
56°
30°
28
57°
30°
29
57°
36°
30
58°
33°
31
56°
31°
1
54°
28°
2
53°
29°
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 53° to 73°, with overnight lows between 28° and 48°. The average high for December is 59° with an average low of 35°. 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.
