The Slovenia resorts with the warmest sea water temperature at this moment are Isola, Portoroz and Strunjan.
Below you can see a list of all popular Slovenia resorts and information about current sea water temperature and averages for current and next months.
| Resort Name | Current Sea Water Temperature |
August 2025 | September 2025 |
|---|---|---|---|
| Isola | 83.6°F | 79.9°F | 77.9°F |
| Portoroz | 83.4°F | 80.3°F | 78.2°F |
| Strunjan | 83.4°F | 80.1°F | 78.0°F |
| Koper | 83.4°F | 79.6°F | 78.0°F |
| Piran | 83.4°F | 80.3°F | 78.2°F |
| Bohinjsko Jezero | 82.2°F | 79.1°F | 75.9°F |
| Cerkno | 82.2°F | 79.0°F | 76.2°F |
| Dolenjske Toplice | 80.2°F | 76.6°F | 74.2°F |
Please see following sea water temperature averages charts for the warmest Slovenia resorts for more details.
You can also get the same information for the every other month of the year when the average sea water temperature is greater then 70°F.
Slovenia Resorts:
NAME
F°
| Bled |  |
+78 |
| Bohinjsko Jezero | |
+78 |
| Bovec |  |
+74 |
| Cerkno | |
+78 |
| Dolenjske Toplice | |
+86 |
| Isola |  |
+90 |
| Koper | |
+90 |
| Ljubljana |  |
+88 |
| Maribor | |
+90 |
| Moravske Toplice | |
+88 |
| Piran | |
+90 |
| Portoroz | |
+90 |
| Rogaska Slatina | |
+86 |
| Smarjeske Toplice | |
+86 |
| Strunjan | |
+90 |
