December weather forecast
Portorož, Slovenia

December, with temperatures dropping to 1.4°C (34.5°F) at night, signals the commencement of winter in Portorož. It's a month of minimal sunlight hours, making it the year’s darkest with the least average sunshine. With a significant dip in sea temperature, swimming activities take a back seat for the majority. Despite being one of the colder months, it carries a charm of its own, with festive decorations illuminating the city's landscapes.

Temperature

The average high-temperature shows a slight dip in December, from November's refreshing 13.2°C (55.8°F) to a chilly 9.7°C (49.5°F). In December, Portorož reports a consistent average low-temperature of 1.4°C (34.5°F) during the nights.

Humidity

In Portorož, Slovenia, the average relative humidity in December is 67%.

Rainfall

In Portorož, in December, it is raining for 10.4 days, with typically 75mm (2.95") of accumulated precipitation. In Portorož, during the entire year, the rain falls for 113.1 days and collects up to 931mm (36.65") of precipitation.

Sea temperature

In December, the average sea temperature is 13.2°C (55.8°F).
Note: At temperatures below 10°C (50°F), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 13°C (55.4°F) is not comfortable.

Daylight

December has the shortest days of the year in Portorož, with an average of 8h and 48min of daylight.
On the first day of December in Portorož, Slovenia, sunrise is at 07:25 and sunset at 16:23. On the last day of the month, sunrise is at 07:45 and sunset at 16:32 CET.

Sunshine

The month with the least sunshine is December, with an average of 3h of sunshine.

UV index

The months with the lowest UV index in Portorož are January, November and December, with an average maximum UV index of 1. A UV Index value of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV rays for average individuals.
Note: A typical high UV index of 1 in December suggests the following recommendations:
Despite most people tolerating extended sun exposure, it is critical to always protect those with sensitive skin, infants, and children. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.