S
M
T
W
T
F
S
29
59°
47°
30
64°
47°
1
65°
46°
2
61°
39°
3
54°
35°
4
55°
37°
5
60°
44°
6
58°
38°
7
52°
37°
8
51°
32°
9
51°
35°
10
52°
33°
11
51°
31°
12
52°
33°
13
57°
32°
14
54°
32°
15
54°
41°
16
56°
40°
17
55°
39°
18
62°
34°
19
55°
29°
20
51°
27°
21
49°
28°
22
51°
31°
23
53°
32°
24
49°
29°
25
49°
28°
26
50°
29°
27
51°
28°
28
50°
29°
29
52°
35°
30
56°
32°
31
55°
29°
1
49°
25°
2
48°
25°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Sylvan
Sylvan's December 2026 forecast shows daily high temperatures ranging from 48° to 65°, with overnight lows between 25° and 47°. The average high for December is 54° with an average low of 34°. 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 Sylvan. See also: January | February | March.