21.12
sun
sun
Day
52°F
SW 3 mph
Precip.
0%
0%
Night
39°F
W 5 mph
Precip.
0%
0%
22.12
mon
mon
Day
50°F
SW 3 mph
Precip.
0%
0%
Night
45°F
W 4 mph
Precip.
100%
100%
23.12
tue
tue
Day
52°F
W 3 mph
Precip.
100%
100%
Night
45°F
SW 7 mph
Precip.
100%
100%
24.12
wed
wed
Day
45°F
SW 15 mph
Precip.
100%
100%
Night
37°F
SW 12 mph
Precip.
100%
100%
25.12
thu
thu
Day
43°F
SW 9 mph
Precip.
0%
0%
Night
34°F
W 7 mph
Precip.
0%
0%
26.12
fri
fri
Day
46°F
SW 7 mph
Precip.
0%
0%
Night
36°F
SW 9 mph
Precip.
0%
0%
27.12
sat
sat
Day
46°F
SW 6 mph
Precip.
0%
0%
Night
32°F
W 4 mph
Precip.
0%
0%
28.12
sun
sun
Day
43°F
SW 4 mph
Precip.
0%
0%
Night
30°F
W 4 mph
Precip.
0%
0%
29.12
mon
mon
Day
43°F
NE 2 mph
Precip.
0%
0%
Night
32°F
W 2 mph
Precip.
0%
0%
30.12
tue
tue
Day
45°F
N 1 mph
Precip.
0%
0%
Night
32°F
W 4 mph
Precip.
0%
0%
31.12
wed
wed
Day
43°F
SW 6 mph
Precip.
0%
0%
Night
28°F
W 14 mph
Precip.
0%
0%
01.01
thu
thu
Day
36°F
SW 8 mph
Precip.
0%
0%
Night
27°F
SW 3 mph
Precip.
0%
0%
02.01
fri
fri
Day
39°F
NE 1 mph
Precip.
0%
0%
Night
28°F
W 2 mph
Precip.
0%
0%
03.01
sat
sat
Day
39°F
N 2 mph
Precip.
0%
0%
Night
30°F
NW 4 mph
Precip.
0%
0%
Sea water temperature in December, °F
Show year:
2025
2024
2023
The average sea water temperature in December of 2025 was 55.9°F. The highest and lowest sea temperatures during the month were 56.8°F and 54.7°F.
Sea water temperature in January, °F
Show year:
2025
2024
2023
The average sea water temperature in January of 2025 was 50.2°F. The highest and lowest sea temperatures during the month were 51.4°F and 48.9°F.
Air temperature in Koper, °F
Precipitation total in Koper, in.
* Charts above show average data for the last 3 years.
Best time for vacation in Koper
Koper on a weather map
Places in Slovenia:
Name
°F
24 Hours Forecast
Koper
Local time: 05:17
December 21, sunday
0600
39°F
W
4 mph
4 mph
0900
41°F
W
4 mph
4 mph
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
