Oprtalj Temperature by Month

Oprtalj, Istria, Croatia has an average annual maximum temperature of 18°C (64°F), ranging from 9°C (48°F) in January to 29°C (84°F) in August. Below you'll find a full monthly breakdown and a comparison with cities worldwide.

With significant temperature fluctuations, Oprtalj enjoys distinct seasons year-round. Nighttime lows range from 20°C (68°F) in August to 2°C (36°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Oprtalj by month:

Temperatures tend to bottom out between 4 AM and 6 AM, then climb to their daily peak around 3 PM. August, the warmest month, sees 299 hours of sunshine.

The chart below shows the average temperature throughout the year:

Oprtalj'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:

Lisbon, Portugal averages 21°C (70°F) annually, warm summers, mild winters, and rain mainly in the cooler months.

Interlaken, Switzerland averages 8°C (46°F) a year, with cold winters and cool summers thanks to its Alpine setting.

New York City, USA averages 17°C (63°F) a year, with hot humid summers and cold winters that bring regular snowfall.

Tokyo, Japan averages 21°C (70°F) a year, with hot summers, cool winters, and a well-defined cherry blossom spring.

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 Oprtalj, 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 29°C (84°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.

Seasonal temperature shifts influence more than just how warm it feels, they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.

Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Oprtalj this rarely lasts long on the ground.

For more on Oprtalj's weather, including monthly rainfall, sunshine hours, and humidity, visit our Oprtalj climate page.