S
M
T
W
T
F
S
29
48°
33°
30
54°
29°
1
50°
27°
2
41°
31°
3
45°
31°
4
48°
33°
5
49°
36°
6
52°
38°
7
52°
40°
8
55°
37°
9
55°
36°
10
52°
36°
11
50°
30°
12
48°
30°
13
39°
29°
14
43°
28°
15
40°
24°
16
39°
22°
17
37°
23°
18
35°
23°
19
37°
22°
20
36°
26°
21
39°
32°
22
42°
34°
23
49°
30°
24
48°
25°
25
42°
17°
26
37°
17°
27
35°
28°
28
35°
20°
29
42°
17°
30
34°
16°
31
30°
20°
1
32°
28°
2
38°
19°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in New Haven
New Haven's December 2026 forecast shows daily high temperatures ranging from 30° to 55°, with overnight lows between 16° and 40°. The average high for December is 43° with an average low of 28°. 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 New Haven. See also: January | February | March.
