S
M
T
W
T
F
S
29
70°
52°
30
73°
49°
1
74°
51°
2
75°
49°
3
76°
45°
4
73°
35°
5
63°
34°
6
57°
33°
7
57°
34°
8
58°
34°
9
60°
35°
10
60°
33°
11
57°
34°
12
58°
38°
13
61°
35°
14
60°
32°
15
59°
32°
16
58°
33°
17
58°
34°
18
59°
35°
19
63°
39°
20
66°
41°
21
69°
46°
22
69°
47°
23
70°
46°
24
69°
45°
25
68°
44°
26
70°
44°
27
69°
43°
28
66°
45°
29
69°
46°
30
70°
45°
31
70°
38°
1
69°
37°
2
63°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Boston
Boston's December 2026 forecast shows daily high temperatures ranging from 57° to 76°, with overnight lows between 32° and 52°. The average high for December is 65° with an average low of 40°. 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 Boston. See also: January | February | March.
