S
M
T
W
T
F
S
29
46°
38°
30
49°
32°
1
53°
28°
2
44°
33°
3
42°
37°
4
53°
32°
5
49°
35°
6
48°
39°
7
49°
38°
8
53°
35°
9
51°
34°
10
46°
36°
11
48°
35°
12
50°
34°
13
47°
28°
14
42°
31°
15
41°
37°
16
50°
33°
17
51°
30°
18
44°
31°
19
47°
28°
20
44°
31°
21
41°
34°
22
49°
33°
23
49°
34°
24
48°
33°
25
47°
28°
26
46°
26°
27
42°
26°
28
40°
26°
29
41°
24°
30
40°
28°
31
39°
31°
1
45°
21°
2
49°
16°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Groton
Groton's December 2026 forecast shows daily high temperatures ranging from 39° to 53°, with overnight lows between 16° and 39°. The average high for December is 46° 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 Groton. See also: January | February | March.
