Average sea water temperature in December:
+55.2°F
| Minimum sea water temperature in December: | 60.1°F |
| Maximum sea water temperature in December: | 50.2°F |
Daily sea water temperature in December, °F
Show year:
2025
2024
2023
The average sea water temperature in December of 2025 was 55.5°F. The highest and lowest sea temperatures during the month were 56.8°F and 53.4°F.
Monthly sea water temperature in Koper, °F
Which Slovenia resorts have warmest sea in December?
| Place name | December 2025 | December 2024 |
|---|---|---|
| Portoroz | 56.2°F | 56.5°F |
| Piran | 56.2°F | 56.5°F |
| Dolenjske Toplice | 56.0°F | 57.1°F |
| Strunjan | 56.0°F | 56.2°F |
| Isola | 55.7°F | 55.9°F |
| Koper | 55.5°F | 55.7°F |
| Cerkno | 53.8°F | 54.0°F |
| Bohinjsko Jezero | 53.6°F | 53.8°F |
Best time for vacation in Koper
Koper on a weather map
Places in Slovenia:
Name
°F
24 Hours Forecast
Koper
Local time: 11:36
January 10, saturday
1200
45°F
S
6 mph
6 mph
1500
45°F
SW
5 mph
5 mph
1800
39°F
W
5 mph
5 mph
2100
34°F
W
4 mph
4 mph
January 11, sunday
0000
34°F
W
4 mph
4 mph
0300
32°F
W
4 mph
4 mph
0600
30°F
W
5 mph
5 mph
0900
30°F
W
7 mph
7 mph
