Swimming in Slovenia in december 2025 Sea temperature by city in december
Do you want to go to the beach in Slovenia in december 2025? Is it the right month to go for pleasant temperatures and staying in the water for a long time? The answer is on this page with the sea temperatures in december in Slovenia by city and our opinion on the chances of enjoying pleasant sea conditions.
Sea temperature in Slovenia in december 2025
Here, find the average sea temperature in Slovenia in december in several coastal cities.
56°F
min: 52°F / max: 60°F
Ankaran
56°F
min: 52°F / max: 60°F
56°F
min: 52°F / max: 60°F
Koper
56°F
min: 52°F / max: 60°F
Portorož
56°F
min: 52°F / max: 60°F
Where should you go swimming in Slovenia in the month of december?
Swimming in Slovenia in december is freezing
In december in Slovenia swimming conditions are generally the same everywhere.
Forget about swimming in Piran, Ankaran, Izola, Koper and Portorož in december! The water temperature is freezing, reaching as low as 52°F (and only 60°F at the best of times). Our advice: plan on sightseeing, and don't bring your beach towel!
Where to go swimming in Slovenia in december: the map of sea temperatures
ideal swimming 
pleasant swimming 
cool swimming 
cold swimming 
freezing swimmingWater temperature and seasonal norms in december
Piran
| December | |||
| Average sea temperature | 56°F | ||
| Minimum sea temperature | 52°F | ||
| Maximum sea temperature | 60°F | ||
| Average outside temperature | 43°F | ||
| Maximum outside temperature | 49°F | ||
| Minimum outside temperature | 38°F | ||
| Precipitation | 9.4in | ||
| Number of days of precipitation | 8 jour(s) (27%) | ||
| Cloud cover | 47% | ||
| Our opinion | freezing swimming |
More information on swimming in Piran in december
Ankaran
| December | |||
| Average sea temperature | 56°F | ||
| Minimum sea temperature | 52°F | ||
| Maximum sea temperature | 60°F | ||
| Average outside temperature | 43°F | ||
| Maximum outside temperature | 49°F | ||
| Minimum outside temperature | 38°F | ||
| Precipitation | 9.4in | ||
| Number of days of precipitation | 8 jour(s) (27%) | ||
| Cloud cover | 47% | ||
| Our opinion | freezing swimming |
Izola
| December | |||
| Average sea temperature | 56°F | ||
| Minimum sea temperature | 52°F | ||
| Maximum sea temperature | 60°F | ||
| Average outside temperature | 43°F | ||
| Maximum outside temperature | 49°F | ||
| Minimum outside temperature | 38°F | ||
| Precipitation | 9.4in | ||
| Number of days of precipitation | 8 jour(s) (27%) | ||
| Cloud cover | 47% | ||
| Our opinion | freezing swimming |
More information on swimming in Izola in december
Koper
| December | |||
| Average sea temperature | 56°F | ||
| Minimum sea temperature | 52°F | ||
| Maximum sea temperature | 60°F | ||
| Average outside temperature | 43°F | ||
| Maximum outside temperature | 49°F | ||
| Minimum outside temperature | 38°F | ||
| Precipitation | 9.4in | ||
| Number of days of precipitation | 8 jour(s) (27%) | ||
| Cloud cover | 47% | ||
| Our opinion | freezing swimming |
Portorož
| December | |||
| Average sea temperature | 56°F | ||
| Minimum sea temperature | 52°F | ||
| Maximum sea temperature | 60°F | ||
| Average outside temperature | 43°F | ||
| Maximum outside temperature | 49°F | ||
| Minimum outside temperature | 38°F | ||
| Precipitation | 9.4in | ||
| Number of days of precipitation | 8 jour(s) (27%) | ||
| Cloud cover | 47% | ||
| Our opinion | freezing swimming |
List of coastal cities in Slovenia
| Piran in december | freezing swimming |
| Ankaran in december | freezing swimming |
| Izola in december | freezing swimming |
| Koper in december | freezing swimming |
| Portorož in december | freezing swimming |