S
M
T
W
T
F
S
29
54°
34°
30
54°
26°
1
40°
23°
2
41°
26°
3
49°
33°
4
47°
32°
5
45°
29°
6
43°
26°
7
39°
22°
8
37°
24°
9
41°
25°
10
44°
31°
11
48°
30°
12
51°
29°
13
48°
30°
14
44°
27°
15
46°
25°
16
45°
24°
17
41°
16°
18
37°
15°
19
36°
10°
20
31°
12°
21
32°
24°
22
39°
15°
23
40°
20°
24
39°
15°
25
38°
24°
26
42°
27°
27
42°
26°
28
41°
24°
29
40°
22°
30
39°
16°
31
39°
14°
1
35°
14°
2
34°
26°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Sylvia
Sylvia's December 2026 forecast shows daily high temperatures ranging from 31° to 54°, with overnight lows between 10° and 34°. The average high for December is 42° with an average low of 23°. 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 Sylvia. See also: January | February | March.