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