S
M
T
W
T
F
S
29
48°
34°
30
54°
30°
1
50°
29°
2
41°
33°
3
46°
33°
4
48°
34°
5
49°
38°
6
52°
39°
7
52°
42°
8
55°
38°
9
55°
37°
10
52°
37°
11
50°
32°
12
48°
30°
13
40°
31°
14
43°
30°
15
40°
25°
16
40°
24°
17
37°
24°
18
36°
25°
19
37°
24°
20
36°
27°
21
40°
33°
22
42°
35°
23
49°
32°
24
49°
26°
25
43°
19°
26
37°
19°
27
36°
30°
28
36°
22°
29
43°
18°
30
35°
18°
31
31°
22°
1
33°
30°
2
39°
21°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Copiague
Copiague's December 2026 forecast shows daily high temperatures ranging from 31° to 55°, with overnight lows between 18° and 42°. The average high for December is 43° with an average low of 29°. 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 Copiague. See also: January | February | March.