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