S
M
T
W
T
F
S
29
43°
30°
30
42°
29°
1
41°
27°
2
41°
27°
3
42°
31°
4
43°
31°
5
44°
32°
6
43°
36°
7
41°
37°
8
42°
35°
9
42°
29°
10
39°
27°
11
51°
31°
12
48°
35°
13
44°
31°
14
50°
29°
15
42°
25°
16
39°
26°
17
37°
29°
18
39°
31°
19
44°
32°
20
45°
34°
21
47°
34°
22
48°
33°
23
48°
34°
24
47°
37°
25
50°
27°
26
51°
27°
27
48°
24°
28
37°
27°
29
36°
31°
30
46°
31°
31
45°
33°
1
47°
35°
2
48°
30°
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 36° to 51°, with overnight lows between 24° and 37°. The average high for December is 44° with an average low of 31°. 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.
