Average sea water temperature in December:
+55.3°F
| Minimum sea water temperature in December: | 60.3°F |
| Maximum sea water temperature in December: | 50.4°F |
Daily sea water temperature in December, °F
Show year:
2025
2024
2023
The average sea water temperature in December of 2025 was 55.7°F. The highest and lowest sea temperatures during the month were 57.2°F and 53.6°F.
Monthly sea water temperature in Isola, °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 Isola
Isola on a weather map
Places in Slovenia:
Name
°F
24 Hours Forecast
Isola
Local time: 12:23
March 17, tuesday
1500

55°F
SW
11 mph
11 mph
1800

52°F
SW
9 mph
9 mph
2100

48°F
W
11 mph
11 mph
March 18, wednesday
0000

46°F
SW
7 mph
7 mph
0300

45°F
SW
5 mph
5 mph
0600

39°F
S
5 mph
5 mph
0900

48°F
SW
9 mph
9 mph
1200

52°F
SW
12 mph
12 mph



























