S
M
T
W
T
F
S
29
62°
39°
30
60°
37°
1
61°
38°
2
62°
37°
3
66°
37°
4
59°
39°
5
63°
49°
6
70°
51°
7
71°
46°
8
72°
37°
9
64°
39°
10
63°
40°
11
64°
47°
12
66°
47°
13
67°
37°
14
69°
35°
15
57°
36°
16
58°
38°
17
61°
44°
18
62°
47°
19
65°
49°
20
69°
50°
21
72°
49°
22
70°
47°
23
70°
40°
24
69°
41°
25
66°
43°
26
67°
46°
27
66°
36°
28
67°
40°
29
57°
35°
30
68°
31°
31
55°
32°
1
53°
37°
2
56°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Smithtown
Smithtown's December 2026 forecast shows daily high temperatures ranging from 53° to 72°, with overnight lows between 31° and 51°. The average high for December is 64° with an average low of 41°. 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 Smithtown. See also: January | February | March.
