S
M
T
W
T
F
S
29
44°
34°
30
46°
36°
1
50°
36°
2
53°
37°
3
53°
36°
4
42°
27°
5
51°
24°
6
53°
22°
7
38°
23°
8
40°
25°
9
41°
18°
10
39°
15°
11
36°
16°
12
35°
19°
13
36°
19°
14
36°
29°
15
41°
33°
16
45°
29°
17
53°
23°
18
48°
22°
19
39°
19°
20
38°
21°
21
39°
18°
22
37°
20°
23
40°
26°
24
45°
29°
25
39°
29°
26
43°
25°
27
42°
24°
28
36°
23°
29
35°
24°
30
38°
18°
31
39°
17°
1
36°
20°
2
35°
25°
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 35° to 53°, with overnight lows between 15° and 37°. The average high for December is 42° with an average low of 25°. 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.
