Measurements:
°C
°F
Koper
48°F
SW 2 mph
Feels like: 48°F
Precip: 0%
World Resorts Slovenia Koper Weather

Koper Sea Water Temperature

Current Sea Water Temperature:
+48.8°F
Maximum Sea Water Temperature in January: 55.2°F
Minimum Sea Water Temperature in January: 46.4°F
Average water temperature in January: 50.7°F

Sea Water Temperature for the Last 10 Days:

January 30 48.8°F January 25 50.0°F
January 29 49.2°F January 24 49.6°F
January 28 48.6°F January 23 49.8°F
January 27 48.8°F January 22 49.8°F
January 26 49.8°F January 21 50.4°F

When is the Warmest Sea for Koper?

According to our data for the last three years for Koper the highest average sea water temperature was in August, July and September.

Average Water Temperature by Month, °F

Sea Water Temperature in August

Select Year: 2025 2024 2023

The average sea surface temperature in August 2025 for Koper was 79.6°F. The maximum and minimum values were 76.8°F and 82.4°F respectively.

Sea Water Temperature in July

Select Year: 2025 2024 2023

The average sea surface temperature in July 2025 for Koper was 81.9°F. The maximum and minimum values were 79.4°F and 85.4°F respectively.

Sea Water Temperature in September

Select Year: 2025 2024 2023

The average sea surface temperature in September 2025 for Koper was 78.0°F. The maximum and minimum values were 75.6°F and 80.6°F respectively.

Best Time to Visit Koper
The most sunny months:
August 23 days
July 22 days
June 20 days
The most warm months:
August 88.9 °F
July 88.7 °F
June 83.6 °F
Warmest sea temperature:
August 81.5 °F
July 81.2 °F
September 76.5 °F
The most cold months:
January 45.0 °F
December 47.8 °F
February 47.9 °F
The most rainy months:
May 7 days
November 6 days
September 6 days
The most windy months:
March 6 mph
February 6 mph
November 6 mph

Koper on the Weather Map

Slovenia Resorts:
NAME
Bled +32
Bohinjsko Jezero +32
Bovec +38
Cerkno +46
Dolenjske Toplice +40
Isola +48
Koper +48
Kranjska Gora +32
Ljubljana +38
Maribor +34
Piran +48
Portoroz +48
Rogaska Slatina +40
Rogla +40
Strunjan +48
24 Hours Weather Forecast
Koper
Local time: 16:17
30 jan, friday
1800 42°F
W
3 mph
2100 40°F
W
4 mph
31 jan, saturday
0000 36°F
W
5 mph
0300 36°F
W
5 mph
0600 34°F
W
6 mph
0900 40°F
W
5 mph
1200 48°F
SW
4 mph
1500 48°F
SW
6 mph