S
M
T
W
T
F
S
29
45°
35°
30
44°
34°
1
45°
38°
2
51°
41°
3
51°
37°
4
46°
33°
5
43°
32°
6
44°
35°
7
50°
34°
8
45°
37°
9
48°
34°
10
44°
32°
11
48°
37°
12
49°
38°
13
46°
39°
14
49°
38°
15
48°
37°
16
48°
37°
17
47°
36°
18
48°
37°
19
48°
37°
20
47°
36°
21
49°
37°
22
48°
38°
23
49°
37°
24
48°
36°
25
47°
37°
26
46°
38°
27
48°
38°
28
48°
37°
29
49°
37°
30
48°
38°
31
49°
38°
1
48°
37°
2
48°
36°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Cardiff
Cardiff's December 2026 forecast shows daily high temperatures ranging from 43° to 51°, with overnight lows between 32° and 41°. The average high for December is 47° with an average low of 37°. 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 Cardiff. See also: January | February | March.
