The Slovenia resorts with the warmest sea water temperature in August are Portoroz, Piran and Strunjan.
Below you can see a list of all popular Slovenia resorts and information about sea water temperature in August for the last two years.
| Resort Name | August 2026 | August 2025 | August 2024 |
|---|---|---|---|
| Portoroz | 85.7°F | 80.3°F | 85.5°F |
| Piran | 85.7°F | 80.3°F | 85.5°F |
| Strunjan | 85.4°F | 80.1°F | 85.2°F |
| Koper | 85.1°F | 79.6°F | 84.8°F |
| Isola | 85.1°F | 79.9°F | 84.9°F |
| Cerkno | 83.7°F | 79.0°F | 82.1°F |
| Bohinjsko Jezero | 83.6°F | 79.1°F | 81.8°F |
| Dolenjske Toplice | 82.1°F | 76.6°F | 82.0°F |
Please see following sea water temperature averages charts for the warmest Slovenia resorts in August.
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 |
