S
M
T
W
T
F
S
29
43°
39°
30
43°
37°
1
41°
34°
2
41°
32°
3
42°
36°
4
46°
38°
5
49°
39°
6
48°
39°
7
40°
26°
8
39°
27°
9
38°
30°
10
39°
35°
11
50°
31°
12
49°
29°
13
39°
30°
14
40°
25°
15
38°
22°
16
35°
22°
17
34°
23°
18
34°
22°
19
35°
22°
20
34°
26°
21
34°
30°
22
36°
33°
23
40°
33°
24
43°
36°
25
47°
28°
26
49°
24°
27
47°
23°
28
33°
26°
29
35°
20°
30
36°
17°
31
31°
18°
1
29°
25°
2
33°
23°
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 29° to 50°, with overnight lows between 17° and 39°. The average high for December is 40° 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 Boston. See also: January | February | March.
