S
M
T
W
T
F
S
29
37°
26°
30
40°
12°
1
31°
16°
2
25°
15°
3
36°
9°
4
31°
8°
5
22°
9°
6
21°
12°
7
24°
16°
8
28°
17°
9
29°
16°
10
26°
14°
11
23°
12°
12
23°
15°
13
26°
7°
14
27°
5°
15
22°
-1°
16
18°
1°
17
16°
15°
18
28°
12°
19
30°
12°
20
30°
6°
21
29°
14°
22
29°
14°
23
30°
13°
24
30°
9°
25
29°
8°
26
23°
10°
27
26°
11°
28
27°
12°
29
30°
13°
30
30°
12°
31
31°
9°
1
29°
8°
2
27°
7°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Chelmsford
Chelmsford's December 2026 forecast shows daily high temperatures ranging from 16° to 40°, with overnight lows between -1° and 26°. The average high for December is 28° with an average low of 11°. 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 Chelmsford. See also: January | February | March.
