S
M
T
W
T
F
S
29
57°
41°
30
57°
32°
1
55°
31°
2
46°
30°
3
44°
28°
4
42°
37°
5
50°
35°
6
53°
29°
7
45°
27°
8
41°
32°
9
42°
31°
10
41°
27°
11
41°
26°
12
39°
27°
13
42°
24°
14
40°
23°
15
37°
22°
16
39°
23°
17
37°
24°
18
Hist. Avg.
44°
29°
19
Hist. Avg.
43°
29°
20
Hist. Avg.
43°
28°
21
Hist. Avg.
43°
28°
22
Hist. Avg.
42°
28°
23
Hist. Avg.
42°
28°
24
Hist. Avg.
42°
28°
25
Hist. Avg.
42°
27°
26
Hist. Avg.
42°
27°
27
Hist. Avg.
41°
27°
28
Hist. Avg.
41°
27°
29
Hist. Avg.
41°
26°
30
Hist. Avg.
41°
26°
31
Hist. Avg.
41°
26°
1
Hist. Avg.
40°
26°
2
Hist. Avg.
40°
26°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
December Weather in Mystic
Mystic's December 2026 forecast shows daily high temperatures ranging from 37° to 57°, with overnight lows between 22° and 41°. The average high for December is 45° with an average low of 29°. 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 Mystic. See also: January | February | March.
