S
M
T
W
T
F
S
29
41°
26°
30
44°
30°
1
45°
29°
2
44°
29°
3
45°
27°
4
42°
25°
5
43°
26°
6
41°
27°
7
43°
25°
8
36°
24°
9
33°
24°
10
34°
23°
11
33°
24°
12
34°
21°
13
35°
18°
14
36°
14°
15
31°
14°
16
30°
16°
17
31°
15°
18
30°
21°
19
33°
20°
20
36°
17°
21
33°
15°
22
30°
15°
23
29°
8°
24
31°
15°
25
27°
12°
26
32°
4°
27
26°
3°
28
22°
4°
29
25°
1°
30
23°
7°
31
25°
18°
1
38°
12°
2
36°
7°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Londonderry
Londonderry's December 2026 forecast shows daily high temperatures ranging from 22° to 45°, with overnight lows between 1° and 30°. The average high for December is 34° with an average low of 18°. 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 Londonderry. See also: January | February | March.
