Average sea water temperature in May:
+64.1°F
| Minimum sea water temperature in May: | 72.5°F |
| Maximum sea water temperature in May: | 56.3°F |
Daily sea water temperature in May, °F
Show year:
2025
2024
2023
The average sea water temperature in May of 2025 was 64.9°F. The highest and lowest sea temperatures during the month were 69.1°F and 60.3°F.
Monthly sea water temperature in Koper, °F
Which Slovenia resorts have warmest sea in May?
| Place name | May 2025 | May 2024 |
|---|---|---|
| Portoroz | 65.3°F | 64.5°F |
| Piran | 65.3°F | 64.5°F |
| Strunjan | 65.2°F | 64.3°F |
| Isola | 65.1°F | 64.1°F |
| Koper | 64.9°F | 64.1°F |
| Cerkno | 63.3°F | 63.4°F |
| Bohinjsko Jezero | 63.2°F | 63.3°F |
| Dolenjske Toplice | 62.3°F | 64.0°F |
Best time for vacation in Koper
Koper on a weather map
Places in Slovenia:
Name
°F
24 Hours Forecast
Koper
Local time: 15:49
December 29, monday
1800

41°F
W
1 mph
1 mph
2100

36°F
NW
2 mph
2 mph
December 30, tuesday
0000

34°F
NW
3 mph
3 mph
0300

34°F
NW
4 mph
4 mph
0600

34°F
W
5 mph
5 mph
0900

36°F
W
5 mph
5 mph
1200

46°F
SW
12 mph
12 mph
1500

43°F
W
14 mph
14 mph

























