Slovenia in December: Weather, Crowds & What to Expect
Climate Map for December
Average temperature across Slovenia in December.
City Weather in December
| City | High | Low | Rain | UV | Feels |
|---|---|---|---|---|---|
| Ljubljana | 3° | -3° | 106 mm | low | Cold |
| Maribor | 4° | -3° | 66 mm | low | Cold |
| Celje | 4° | -2° | 76 mm | low | Cold |
| Kranj | 3° | -4° | 113 mm | low | Freezing |
| Koper | 9° | 4° | 85 mm | low | Cold |
| Novo Mesto | 4° | -2° | 82 mm | low | Cold |
| Velenje | 3° | -3° | 80 mm | low | Cold |
High / low are average daily temperatures (°C). “Feels” reflects how hot or cold it feels, allowing for humidity.
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.