19.12
fri
fri
Day
54°F
N 1 mph
Precip.
66%
66%
Night
46°F
S 1 mph
Precip.
88%
88%
20.12
sat
sat
Day
55°F
SW 2 mph
Precip.
0%
0%
Night
41°F
W 4 mph
Precip.
0%
0%
21.12
sun
sun
Day
54°F
SW 2 mph
Precip.
0%
0%
Night
46°F
W 2 mph
Precip.
0%
0%
22.12
mon
mon
Day
55°F
NW 4 mph
Precip.
100%
100%
Night
46°F
W 3 mph
Precip.
100%
100%
23.12
tue
tue
Day
52°F
SW 9 mph
Precip.
0%
0%
Night
41°F
W 6 mph
Precip.
0%
0%
24.12
wed
wed
Day
48°F
W 7 mph
Precip.
0%
0%
Night
39°F
W 7 mph
Precip.
0%
0%
25.12
thu
thu
Day
46°F
SW 7 mph
Precip.
41%
41%
Night
37°F
W 13 mph
Precip.
100%
100%
26.12
fri
fri
Day
45°F
SW 11 mph
Precip.
23%
23%
Night
36°F
W 7 mph
Precip.
0%
0%
27.12
sat
sat
Day
45°F
SW 7 mph
Precip.
0%
0%
Night
34°F
W 8 mph
Precip.
0%
0%
28.12
sun
sun
Day
43°F
SW 9 mph
Precip.
0%
0%
Night
30°F
W 16 mph
Precip.
0%
0%
29.12
mon
mon
Day
37°F
SW 12 mph
Precip.
0%
0%
Night
27°F
W 4 mph
Precip.
0%
0%
30.12
tue
tue
Day
37°F
NE 2 mph
Precip.
0%
0%
Night
27°F
W 3 mph
Precip.
0%
0%
31.12
wed
wed
Day
41°F
SW 2 mph
Precip.
0%
0%
Night
28°F
W 4 mph
Precip.
0%
0%
01.01
thu
thu
Day
41°F
N 3 mph
Precip.
0%
0%
Night
34°F
NW 2 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 56.0°F. The highest and lowest sea temperatures during the month were 56.8°F and 55.0°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: 21:16
December 20, saturday
0000
46°F
S
1 mph
1 mph
0300
46°F
S
2 mph
2 mph
0600
46°F
S
1 mph
1 mph
0900
45°F
SW
2 mph
2 mph
1200
55°F
SW
2 mph
2 mph
1500
55°F
S
2 mph
2 mph
1800
50°F
SW
3 mph
3 mph
2100
43°F
W
4 mph
4 mph
