Koper Temperature by Month
The average annual maximum temperature in Koper, Carinthia, Slovenia is 18°C (64°F), with daytime highs ranging from 9°C (48°F) in January to 28°C (82°F) in August. This page covers monthly averages, day-night differences, and how Koper compares to cities worldwide.
Koper Monthly Temperatures
Depending on the time of the year, temperatures range from warm to cold in Koper. Nighttime lows follow the same pattern, ranging from 20°C (68°F) to 3°C (37°F).
The chart below illustrates the average maximum day and minimum night temperatures in Koper by month:
The minimum temperature is often recorded between 4 AM and 6 AM, while the highest temperature is usually reached at 3 PM, when the sun's heating effect is strongest. August, the warmest month, gets 299 hours of sunshine.
The chart below shows the average temperature throughout the year:
Daily Historical Temperatures
50-year average (1976-2025)
Average high and low temperatures for each day of the month based on long-term records.
Average temperatures in June
Historical Koper Temperatures: 1976-2026
Browse day-by-day temperature records for Koper spanning 51 years. Select any month and year to see actual high and low temperatures recorded on each day.
Temperature: Koper vs Slovenia
The map below shows the annual temperature across Slovenia. You can also select individual months if you want to compare a specific time of year.
very warm
warm
pleasant
moderate
cold
very cold
Koper vs World: Temperature Compared
Koper's average annual maximum temperature is 18°C (64°F). To put that in context, here's how it compares to a few well-known destinations:
Barcelona, Spain has an annual average of around 21°C (70°F), with warm summers and mild, fairly short winters.
Reykjavík, Iceland averages 9°C (48°F) a year — mild summers by Icelandic standards, but cold winters and frequent wind.
Beijing, China averages 20°C (68°F) annually, but with big seasonal swings — very cold winters and hot summers.
Perth, Australia averages 25°C (77°F) annually, with a classic Mediterranean climate — hot dry summers and mild wet winters.
What Does the Temperature Feel Like in Koper?
Temperature alone doesn't tell the whole story — humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.
In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.
In Koper, January is the coolest month, with average highs of 9°C (48°F) and humidity around 67% — considered high. In August, the warmest month, temperatures average 28°C (82°F) with 51% humidity — conditions that feel moderate. For a full picture, see our humidity page.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
Global average temperatures have risen by around 1.2°C since the pre-industrial era, and the effects are visible across many regions. Winters are milder on average, with fewer frost days and less snow in many parts of the world. Heatwaves are more frequent and more intense, and Europe's summers of 2018, 2019, and 2020 all set records.
Summers are also getting drier in some areas, while winter rainfall has increased in others. This contributies to higher river levels and more flooding. In many countries, spring arrives earlier and autumn lasts longer. It has knock-on effects for wildlife, agriculture, and local ecosystems.
For more on Koper's weather — including monthly rainfall, sunshine hours, and humidity — visit our Koper climate page.
