Current sea water temperature:
+55.4°F
| Minimum sea water temperature in December: | 60.1°F |
| Maximum sea water temperature in December: | 50.2°F |
| Average sea water temperature in December: | 55.2°F |
| more information | |
14 days
forecast
forecast
| Koper |
monthly
weather
weather
| Koper |
Sea water temperature for the last 10 days:
| December 21 | 55.4°F | December 16 | 55.4°F |
| December 20 | 54.7°F | December 15 | 55.2°F |
| December 19 | 55.0°F | December 14 | 56.3°F |
| December 18 | 55.2°F | December 13 | 55.8°F |
| December 17 | 55.4°F | December 12 | 55.2°F |
Monthly sea water temperature, °F
When is the warmest sea in Koper?
Based on the data about daily sea water temperature for the last three years the warmest sea in Koper was noticed in August, July and September.
Monthly Sea Temperatures in Koper, °F
Sea water temperature in August, °F
Show year:
2025
2024
2023
The average sea water temperature in August of 2025 was 76.7°F. The highest and lowest sea temperatures during the month were 79.2°F and 74.1°F.
Sea water temperature in July, °F
Show year:
2025
2024
2023
The average sea water temperature in July of 2025 was 78.7°F. The highest and lowest sea temperatures during the month were 81.9°F and 76.5°F.
Sea water temperature in September, °F
Show year:
2025
2024
2023
The average sea water temperature in September of 2025 was 75.2°F. The highest and lowest sea temperatures during the month were 77.5°F and 73.0°F.
current
weather
weather
| Koper |
weather in
December
December
| Koper |
Best time for vacation in Koper
Koper on a weather map
Places in Slovenia:
Name
°F
24 Hours Forecast
Koper
Local time: 11:32
December 21, sunday
1200
52°F
SW
3 mph
3 mph
1500
52°F
SW
2 mph
2 mph
1800
46°F
W
4 mph
4 mph
2100
39°F
W
5 mph
5 mph
December 22, monday
0000
39°F
W
5 mph
5 mph
0300
37°F
W
5 mph
5 mph
0600
37°F
W
4 mph
4 mph
0900
41°F
W
5 mph
5 mph
