December sees winter conditions returning: lowlands are chilly while mountain resorts build snow cover for the ski season. Holiday markets and festive events increase visitor interest, especially around Christmas and New Year.
SeasonLow SeasonTemperature −1 to 6°C (30 to 43°F)Crowds LowPrices Low
High seasonShoulderLow season
Weather by City in December
CityLow / highRain
Ljubljana
Cold
-3°3° 106 mm
Maribor
Freezing
-3°4° 66 mm
Celje
Cold
-2°4° 76 mm
Kranj
Freezing
-4°3° 113 mm
Koper
Cold
4°9° 85 mm
Novo Mesto
Cold
-2°4° 82 mm
Velenje
Cold
-3°3° 80 mm
Average daily low and high (°C) and monthly rainfall. The badge shows how it feels, allowing for humidity.
Temperature map
-30°-20°-10°0°10°20°30°40°
Average temperature across Slovenia in December.
Where to Go in Slovenia in December
Julian Alps & Alpine Slovenia
Bled, Bohinj, Kranjska Gora, Triglav
Late winter melt starts in sheltered valleys while high summits keep snow; spring arrives unevenly with bluebird days alternating with snow showers. End-of-season ski touring becomes popular as lower slopes thin out; Crevasses on glaciers are generally limited in Slovenia but summit approaches remain technical. Plan for mixed conditions-waterproof outer layers, warm insulating mid-layers, and flexible plans if trails or huts are still under snow.
Soča Valley & Goriška Hills
Bovec, Kobarid, Tolmin, Nova Gorica, Goriška Brda
Midspring into early summer sees the valley settle into reliably warm days and cool nights, perfect for multi-day rafting, climbing and trekking itineraries. Vineyards in Brda are verdant and small-family wineries begin tastings; weekend crowds pick up but the region still feels relaxed compared to coastal hot spots. Bring layered clothing for temperature swings, and reserve adventure activities in advance during June and July.
Slovenian Coast & Karst
Piran, Koper, Portorož, Škocjan Caves, Lipica
Midspring into early summer sees reliably pleasant weather for coastal exploration and cave visits; warm days are common while nights remain cool. This is an excellent window for cycling the coastline, visiting vineyards in the Karst, and timing trips to the Škocjan Caves before peak tourist season. Comfortable walking shoes and a windproof layer will cover most conditions.
Ljubljana & Central Slovenia
Ljubljana, Kamnik, Radovljica, Central Sava Valley
description’:’The central lowland around Ljubljana has a continental climate with warm summers, cold winters and notable seasonal swings. It’s an excellent year-round base: spring and autumn are especially pleasant for city sightseeing, summer brings festivals and crowds, while winter can be snowy and atmospheric. Expect fog in valleys in late autumn and winter, and occasional summer storms.’
Northeast & Southeast Lowlands
Prekmurje, Ptuj, Murska Sobota, Dolenjska, Bela Krajina, Rogaška
Midspring into early summer yields reliably warm, pleasant weather ideal for winery visits, cycling routes and quiet village stays-this is a strong shoulder-season for relaxed travel in the eastern and southern lowlands. Fields are green and farmers’ markets are full of fresh produce; insect repellent for riverside picnics and a light jacket for evening tastiness remain good packing choices.
Events & Festivals in December
Advent & Christmas markets
Christmas markets and Advent events are common in towns and cities, notably in Ljubljana and other regional centres.
Planning a trip to Slovenia?
See how December compares with the rest of the year, then read the full guide.
