S
M
T
W
T
F
S
29
48°
38°
30
53°
41°
1
52°
40°
2
52°
40°
3
54°
38°
4
50°
37°
5
52°
36°
6
49°
38°
7
52°
37°
8
45°
34°
9
42°
32°
10
42°
29°
11
40°
34°
12
42°
33°
13
43°
31°
14
41°
27°
15
40°
28°
16
39°
30°
17
40°
29°
18
39°
34°
19
48°
33°
20
48°
25°
21
41°
26°
22
37°
25°
23
36°
27°
24
39°
28°
25
42°
26°
26
47°
20°
27
36°
20°
28
32°
21°
29
35°
21°
30
35°
27°
31
38°
29°
1
49°
22°
2
45°
18°
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 32° to 54°, with overnight lows between 18° and 41°. The average high for December is 44° with an average low of 30°. 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.
