Current Sea Water Temperature:
+82.6°F
| Maximum Sea Water Temperature in July: | 89.2°F |
| Minimum Sea Water Temperature in July: | 75.6°F |
| Average water temperature in July: | 81.3°F |
| detailed information | |
Sea Water Temperature for the Last 10 Days:
| July 21 | 82.6°F | July 16 | 83.6°F |
| July 20 | 84.4°F | July 15 | 83.6°F |
| July 19 | 85.0°F | July 14 | 82.8°F |
| July 18 | 85.0°F | July 13 | 82.8°F |
| July 17 | 85.2°F | July 12 | 82.6°F |
When is the Warmest Sea for Koper?
According to our data for the last three years for Koper the highest average sea water temperature was in August, July and September.
Average Water Temperature by Month, °F
Sea Water Temperature in August
The average sea surface temperature in August 2025 for Koper was 79.6°F. The maximum and minimum values were 76.8°F and 82.4°F respectively.
Sea Water Temperature in July
The average sea surface temperature in July 2026 for Koper was 83.4°F. The maximum and minimum values were 81.2°F and 87.6°F respectively.
Sea Water Temperature in September
The average sea surface temperature in September 2025 for Koper was 78.0°F. The maximum and minimum values were 75.6°F and 80.6°F respectively.
Slovenia Resorts:
NAME
F°
| Bled |  |
+50 |
| Bohinjsko Jezero | |
+50 |
| Bovec | |
+50 |
| Cerkno | |
+52 |
| Dolenjske Toplice | |
+56 |
| Isola | |
+72 |
| Koper | |
+72 |
| Kranjska Gora | |
+50 |
| Ljubljana | |
+54 |
| Maribor | |
+52 |
| Piran | |
+72 |
| Portoroz | |
+72 |
| Rogaska Slatina |  |
+54 |
| Smarjeske Toplice | |
+56 |
| Strunjan | |
+64 |
Countries:
NAME
POPULARITY
24 Hours Weather Forecast
Koper
Local time: 01:58
22 jul, wednesday
| 0300 |  |
72°F | W 9 mph |
| 0600 |  |
62°F | W 6 mph |
| 0900 | |
76°F | SW 9 mph |
| 1200 | |
84°F | S 7 mph |
| 1500 |  |
84°F | SE 7 mph |
| 1800 | |
82°F | E 8 mph |
| 2100 | |
66°F | NE 1 mph |
23 jul, thursday
| 0000 |  |
64°F | W 4 mph |