S
M
T
W
T
F
S
29
52°
38°
30
53°
38°
1
52°
32°
2
40°
28°
3
40°
29°
4
48°
33°
5
49°
36°
6
41°
28°
7
38°
22°
8
36°
21°
9
36°
23°
10
38°
27°
11
42°
27°
12
44°
28°
13
43°
27°
14
38°
22°
15
38°
26°
16
39°
29°
17
41°
27°
18
41°
22°
19
38°
20°
20
36°
19°
21
34°
20°
22
35°
24°
23
41°
24°
24
36°
25°
25
35°
18°
26
35°
18°
27
34°
19°
28
34°
18°
29
33°
21°
30
34°
20°
31
34°
17°
1
34°
13°
2
32°
12°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Mount Vernon
Mount Vernon's December 2026 forecast shows daily high temperatures ranging from 32° to 53°, with overnight lows between 12° and 38°. The average high for December is 39° with an average low of 24°. 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 Mount Vernon. See also: January | February | March.
