Koper in December
Find out everything about the water temperature in Koper in December. Average, minimum and maximum recorded temperatures as well as daily temperature in December for the last two years. Compare the current month's sea temperature data with other months of the year.
Water temperature in December
Minimum:
50.6 °F
Average:
55.4 °F
Maximum:
60.0 °F
Sea water temperature in Koper in December
In the city of Koper, the month of December is too cold for swimming. The minimum recorded temperature during this month was 50.6°F on December 31, 2018, with an average temperature being 55.4°F and a maximum temperature reaching 60.0°F on December 4, 2019.
| Date | 10 years average | 2025 | 2024 |
|---|---|---|---|
| Dec 1 | 58.0°F | 56.7°F | 58.8°F |
| Dec 2 | 57.7°F | 56.6°F | 58.4°F |
| Dec 3 | 57.6°F | 56.6°F | 58.1°F |
| Dec 4 | 57.3°F | 56.5°F | 57.8°F |
| Dec 5 | 57.2°F | 56.4°F | 58.4°F |
| Dec 6 | 57.1°F | 56.7°F | 58.1°F |
| Dec 7 | 56.9°F | 56.6°F | 57.3°F |
| Dec 8 | 56.8°F | 56.9°F | 57.6°F |
| Dec 9 | 56.6°F | 57.0°F | 57.1°F |
| Dec 10 | 56.4°F | 56.5°F | 57.5°F |
| Dec 11 | 56.3°F | 55.9°F | 57.5°F |
| Dec 12 | 56.1°F | 55.6°F | 56.9°F |
| Dec 13 | 56.0°F | 56.0°F | 57.2°F |
| Dec 14 | 55.8°F | 56.5°F | 56.9°F |
| Dec 15 | 55.6°F | 55.3°F | 57.0°F |
| Dec 16 | 55.5°F | 55.4°F | 56.9°F |
| Dec 17 | 55.3°F | 55.4°F | 55.7°F |
| Dec 18 | 55.1°F | 55.3°F | 55.4°F |
| Dec 19 | 55.1°F | 55.2°F | 55.4°F |
| Dec 20 | 55.1°F | 55.3°F | 55.3°F |
| Dec 21 | 55.1°F | 55.2°F | 55.6°F |
| Dec 22 | 54.7°F | 54.8°F | 54.8°F |
| Dec 23 | 54.4°F | 54.6°F | 54.3°F |
| Dec 24 | 53.9°F | 54.1°F | 53.9°F |
| Dec 25 | 53.6°F | 53.8°F | 54.0°F |
| Dec 26 | 53.4°F | 53.6°F | 53.3°F |
| Dec 27 | 53.1°F | 53.3°F | 53.0°F |
| Dec 28 | 53.0°F | 53.2°F | 52.3°F |
| Dec 29 | 52.8°F | 52.9°F | 51.8°F |
| Dec 30 | 52.8°F | 52.9°F | 52.0°F |
| Dec 31 | 52.4°F | 52.6°F | 51.3°F |
In Koper, the months July through September offer comfortable swimming conditions, which amounts to 96 swimming days.
The warmest water in Koper was recorded on July 23, 2015, reaching a 85.2°F. While the coldest temperature occurred on March 10, 2022, dipping to 47.0°F. The average readings by season are 51.8°F in Winter, 56.7°F in Spring, 76.8°F in Summer, and 67.6°F in Autumn.
December's average temperature is a slight drop from November's average of 61.5°F. In January, the temperature is expected to decrease further, potentially averaging around 50.9°F.
Popular neighboring cities and resorts
| City | Water temperature* | Distance** |
|---|---|---|
| Trieste |
55.2°F
|
7mi |
| Poreč |
57.6°F
|
23mi |
| Lignano Sabbiadoro |
50.7°F
|
31mi |
| Lovran |
56.3°F
|
32mi |
| Rovinj |
57.8°F
|
32mi |
| Rijeka |
56.4°F
|
38mi |
| Rabac |
56.6°F
|
38mi |
| Caorle |
50.7°F
|
41mi |
* current water temperature in this city
** straight line distance from Koper