December Weather in , Slovenia

Last updated: August 27, 2025

December in Slovenia unveils a wintry charm, characterized by a maximum temperature of 15°C (60°F) and a chilly average of 7°C (44°F). As the month progresses, temperatures can dip as low as -1°C (30°F), setting the stage for a cozy, festive atmosphere. Visitors can expect 150 mm (5.9 in) of precipitation over approximately 12 wet days, creating a lush backdrop while also reminding everyone to bundle up. With an average humidity of 88%, December often feels a bit crisper, intensifying the seasonal magic that envelops this picturesque European gem during the holidays.

December Temperature in

In December, Slovenia experiences a notable shift as winter sets in, with temperatures marking a significant drop compared to previous months. The average temperature hovers around 7°C (44°F), while nighttime lows can reach as low as -1°C (30°F), creating a chilly atmosphere perfect for winter activities. With daytime highs peaking at 15°C (60°F), December offers a pleasant mix of crisp air and festive charm. As the year winds down, the transition from autumn’s mild temperatures to the colder conditions of winter is evident, inviting visitors to embrace the cozy warmth of local culture and seasonal celebrations.

December Weather in : Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in , showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In , December typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec404448556272757668595144
Data source: Temperature data for generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in

In December, Slovenia experiences a substantial amount of precipitation, with 150 mm (5.9 in) recorded over 12 days. This marks a notable increase compared to the relatively dry summer months, particularly July and August, which saw just 65 mm and 70 mm respectively. As the year concludes, precipitation builds significantly, with November already at 176 mm (6.9 in). The trend indicates that the late autumn and winter months bring considerable moisture, essential for replenishing local ecosystems. With December's rainfall, the region wraps up the year on a wet note, setting the stage for a dynamic start to the year ahead.

December Precipitation Trends in

The chart displays monthly precipitation patterns in , with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In , December typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec5611872103142876570164107176150
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

December Humidity in

In December, Slovenia experiences a humidity level of 88%, reflecting a trend that sees the final month of the year nearly mirroring January’s high of 88%. This sharp rise in humidity starts in October at 83%, peaks in November, and maintains a constant presence as the year draws to a close. Interestingly, while warmer months like July and August showcase much lower humidity levels—at 63% and 51% respectively—the onset of winter brings humidity back to higher proportions. As the cold sets in, the atmosphere becomes noticeably more humid, contrasting with the drier summer months and creating a brisk yet moist climate perfect for cozy winter experiences.

December Average Humidity in

This chart illustrates the average monthly humidity levels in , with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%82%73%73%70%69%63%51%64%83%89%88%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in

As December rolls in, Slovenia experiences a notable dip in the UV Index, which drops back to 2, reflecting a low exposure category. With a burn time of 45 minutes, it's a reminder to enjoy the outdoors without the same level of sun protection required in the peak summer months. This seasonal decline follows a pattern established from the prior months, where the UV Index peaked at 9 in July and June, indicative of the very high risk associated with summer sun exposure. As we transition through the year, understanding these trends is essential for optimizing outdoor activities while taking necessary precautions. For more detailed information, check out the UV Index specific to Slovenia.

Maximum UV Index Levels in for December

The chart shows the monthly maximum UV Index (UVI) for in December, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In December, the maximum UV index in typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235689987532
Data source: December UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

December Sunshine in

In December, Slovenia enjoys a modest yet inviting 207 hours of sunshine, marking a slight dip from the previous month. This decrease isn't unusual as the year winds down, with sunshine hours gradually ascending from 182 hours in January to a peak of 430 hours in July. The trend showcases a clear seasonal progression, where longer, sunlit days are most prevalent in the summer months, creating a vibrant contrast with the winter's more subdued daylight. As December approaches, the shorter days cast a cozy charm over Slovenia, reminding us that even in the chill of winter, there's a delicate beauty to the soft, golden rays that beckon amidst the frosty landscape.

Monthly Sunshine Duration in : December Highlighted

The December sunshine duration represents the total number of hours experiences direct sunlight during the month of December, excluding cloudy or obstructed periods. This chart compares the sunshine duration of December with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec182h223h315h344h372h417h430h397h326h293h229h207h
Data source: December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in During December

In Slovenia, December heralds a cool, wintry landscape, but the chance of sunny weather remains relatively low, at just 38%. This percentage follows a slight dip from November's 37%, marking a trend of dwindling sunshine as the year closes. As we transition from the brighter summer months—when the likelihood of sunshine peaks at 61% in August—December stands out with its limited sunny days. As winter draws near, the sun becomes a rare presence, making those occasional clear skies all the more precious to locals and visitors alike.

Percentage of Sunny Days in December in

The chart illustrates the percentage of sunny days in throughout the year, with December highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec32%41%63%44%40%55%51%61%59%50%37%38%
Data source: December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in in December

As we move through the year in Slovenia, daylight duration reflects the changing seasons in a captivating rhythm. December, with its 8 hours of daylight, represents the twilight of the year, where the sun makes a brief but precious appearance. This marks a noticeable decrease from the more generous 14 hours in May and 15 hours during the summer months of June and July. The transition from the vibrant sunlit days of spring to the hibernation of winter is evident as daylight diminishes from 11 hours in March to the year's darkest days in December. The gradual shift highlights the beauty of seasonal variation, inviting reflections on the cozy charm of Slovenia's December while eagerly anticipating the return of longer days in the coming months.

Average Daylight Hours in for December

The chart illustrates the variation in daylight duration in throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 8m10h 22m11h 56m13h 32m14h 55m15h 37m15h 15m14h 1m12h 29m10h 53m9h 28m8h 44m
Data source: daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in

As December settles in Slovenia, the average wind speed drops to 2.3 m/s (5 mph), marking one of the calmer months of the year. This transition reflects a notable trend: after a gradual increase in winds during the fall, peaking in October and November with speeds of 3.6 m/s (8 mph) and 3.7 m/s (8 mph) respectively, winter welcomes a gentle breeze. The lower wind speeds of December not only invite a sense of tranquility but also signal a shift towards a colder season, mirroring the steady decline in wind intensity observed from early autumn. As nature prepares for the winter chill, the subdued December winds offer a serene wrap-up to the year.

Average December Wind Speed in

The chart displays monthly wind speed patterns in , with values for each month shown alongside December's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how December's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec3.02.82.63.03.22.22.52.82.43.63.72.3 m/s
Data source: December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in Compares to Other Months

Weather in varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in , focusing on differences in temperature, rainfall, humidity, and UV levels.

In December, temperatures tend to be milder, with a minimum of -1°C (30°F) and a maximum of 15°C (60°F), while January sees cooler conditions, dipping to a low of -7°C (20°F) and a high of 13°C (56°F). December also brings more rainfall, with 150 mm (5.9 in) of precipitation over 12 days compared to January's 56 mm (2.2 in) over just 7 days. Both months experience similar humidity levels at 88%, creating a crisp atmosphere as winter sets in. For a detailed look at January's weather, check out weather in January.

December presents a chillier climate compared to February, with minimum temperatures dipping to -1°C (30°F) versus February's -6°C (22°F). While both months feature an average temperature of 7°C (44°F), February enjoys slightly warmer maximums, reaching up to 19°C (67°F) compared to December's 15°C (60°F). Precipitation is relatively high in December at 150 mm (5.9 in) over 12 days, which is slightly more than February's 118 mm (4.6 in) across 10 days. Additionally, December experiences higher humidity levels at 88%, while February has a more comfortable 82%. For further details on February's weather, you can explore weather in February.

In December, temperatures typically range from a chilly minimum of -1°C (30°F) to a mild maximum of 15°C (60°F), with an average of 7°C (44°F). The month sees considerable precipitation, totaling 150 mm (5.9 in) spread across about 12 days, resulting in a high humidity level of 88%. In contrast, March experiences a more significant temperature range, with lows of -7°C (20°F) and highs reaching up to 21°C (70°F), averaging around 9°C (48°F). Precipitation decreases notably to 71 mm (2.8 in) over 8 days, accompanied by a lower humidity of 73%. For more details, you can check the weather in March.

In December, temperatures range from a chilly -1°C (30°F) at night to a mild 15°C (60°F) during the day, with an average of 7°C (44°F). This month experiences higher precipitation, with approximately 150 mm (5.9 in) spread over 12 days, contributing to a humid atmosphere with 88% humidity. In contrast, April brings a more temperate climate, with minimum temperatures of 1°C (34°F) and maximums reaching 25°C (77°F), averaging around 13°C (55°F). Precipitation decreases to about 103 mm (4.0 in) over 10 days, and humidity drops to a more comfortable 73%. For more details, you can view the weather in April.

In December, the weather tends to be much colder, with temperatures ranging from a minimum of -1°C (30°F) to a maximum of 15°C (60°F), averaging around 7°C (44°F). The month also experiences higher precipitation, with around 150 mm (5.9 in) falling over 12 days, accompanied by high humidity levels of 88%.

In contrast, May presents a significantly milder climate, with temperatures ranging from a minimum of 7°C (46°F) to a maximum of 27°C (81°F), averaging 17°C (63°F). While it experiences slightly less precipitation at 142 mm (5.6 in) over 17 days, the humidity is lower at 70%. For more details about this delightful spring month, check out the weather in May.

In December, temperatures range from a chilly minimum of -1°C (30°F) to a mild maximum of 15°C (60°F), with an average of about 7°C (44°F). The month sees significant precipitation of 150 mm (5.9 in) over 12 days, contributing to a high humidity level of 88%. In contrast, June brings much warmer weather, with temperatures ranging from a minimum of 11°C (53°F) to a maximum of 33°C (92°F), averaging around 22°C (72°F). The precipitation in June is lower at 87 mm (3.4 in) spread over just 8 days, and the humidity drops to a more comfortable 69%. For more details about the weather in June, visit weather in June.

In December, the weather is quite chilly, with temperatures ranging from a minimum of -1°C (30°F) to a maximum of 15°C (60°F), and an average temperature of 7°C (44°F). This month is also characterized by significant precipitation, totaling 150 mm (5.9 in) over approximately 12 days and a high humidity level of 88%. In contrast, July brings much warmer conditions, with minimum temperatures of 16°C (61°F) and maximum temperatures soaring up to 33°C (91°F), averaging around 24°C (75°F). Precipitation is lighter in July, amounting to 65 mm (2.6 in) over just 8 days, and humidity is lower at 63%. For more detailed insights, you can check the weather in July.

December and August present starkly contrasting weather conditions. In December, temperatures range from a chilly -1°C (30°F) to a mild 15°C (60°F), with an average of 7°C (44°F). The month is characterized by significant precipitation, accumulating to 150 mm (5.9 in) over approximately 12 days, coupled with high humidity levels at 88%. In contrast, August boasts much warmer temperatures, with a minimum of 15°C (59°F) and a maximum reaching up to 34°C (94°F), averaging around 25°C (77°F). It is also drier, with only 70 mm (2.7 in) of rainfall over 7 days and a more comfortable humidity level of 51%. For a closer look at the specifics, you can find details on the weather in August.

December and September present contrasting weather conditions. In December, temperatures range from a chilly -1°C (30°F) to a mild 15°C (60°F), with an average of 7°C (44°F). This month typically experiences higher humidity at 88% and an average of 150 mm (5.9 in) of precipitation over 12 days. In stark contrast, September boasts much warmer temperatures, with a minimum of 9°C (49°F), an average of 20°C (68°F), and a maximum of 32°C (90°F). It has slightly higher precipitation at 164 mm (6.4 in), but over just 10 days, making it feel less wet. For more information on the weather conditions during September, check out weather in September.

December weather is notably colder than October, with average temperatures ranging from a minimum of -1°C (30°F) to a maximum of 15°C (60°F), compared to October's milder averages of 6°C (44°F) to 23°C (74°F). Precipitation is also more pronounced in December, accumulating to 150 mm (5.9 in) over 12 days, as opposed to October's 107 mm (4.2 in) over 10 days. Additionally, humidity levels rise slightly in December to 88%, compared to October's 83%, contributing to a more pronounced chill in the air. For a detailed look at the conditions, check out the weather in October.

In comparing the weather between December and November, December tends to be colder, with average temperatures ranging from a minimum of -1°C (30°F) to a maximum of 15°C (60°F), while November experiences milder conditions with temperatures ranging from 1°C (34°F) to 20°C (68°F). Interestingly, despite December being colder, it has slightly less precipitation at 150 mm (5.9 in) compared to November's 176 mm (6.9 in), although both months have rain on about 12 days. Humidity remains fairly stable, with December at 88% and November at 89%. For a detailed look at November's weather, you can check weather in November.

Compare 's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in

As the year draws to a close, December's weather in Koper-Capodistria reveals a stark contrast to the preceding months. With chilly temperatures that can dip below freezing and an average that hovers around 7°C (44°F), this month embraces the heart of winter. The air is thick with humidity, often reaching 88%, contributing to the damp feel of the season. Additionally, December experiences a notable increase in precipitation, with around 150 mm (5.9 in) spread over approximately 12 days, making it one of the wetter months of the year. This shift encourages a cozy atmosphere, perfect for gathering indoors as the landscape becomes gracefully drenched. For those interested in more detailed insights, explore further at Climate.