Average sea water temperature in September:
+74.1°F
| Minimum sea water temperature in September: | 82.2°F |
| Maximum sea water temperature in September: | 68.9°F |
Daily sea water temperature in September, °F
Show year:
2026
2025
2024
The average sea water temperature in September of 2026 was 78.2°F. The highest and lowest sea temperatures during the month were 81.3°F and 75.0°F.
Monthly sea water temperature in Isola, °F
Which Slovenia resorts have warmest sea in September?
| Place name | September 2026 | September 2025 |
|---|---|---|
| Portoroz | 78.6°F | 75.3°F |
| Piran | 78.6°F | 75.3°F |
| Strunjan | 78.4°F | 75.2°F |
| Koper | 78.3°F | 75.2°F |
| Isola | 78.2°F | 75.1°F |
| Cerkno | 76.6°F | 73.6°F |
| Bohinjsko Jezero | 76.4°F | 73.3°F |
| Dolenjske Toplice | 76.0°F | 71.7°F |
Best time for vacation in Isola
Isola on a weather map
Places in Slovenia:
Name
°F
24 Hours Forecast
Isola
Local time: 16:10
September 22, tuesday
1800
66°F
S
2 mph
2 mph
2100
57°F
W
4 mph
4 mph
September 23, wednesday
0000
55°F
W
6 mph
6 mph
0300
57°F
W
2 mph
2 mph
0600
54°F
W
4 mph
4 mph
0900
59°F
W
3 mph
3 mph
1200
66°F
SE
5 mph
5 mph
1500
66°F
SE
6 mph
6 mph
