September brings comfortable temperatures and fewer crowds, a good time for hiking and wine tourism during the harvest period. Prices and visitor numbers ease compared with summer while many services remain available.
SeasonShoulderTemperature 13 to 23°C (55 to 73°F)Crowds ModeratePrices Moderate
High seasonShoulderLow season
Weather by City in September
CityLow / highRain
Ljubljana
Cool
10°21° 136 mm
Maribor
Cool
10°21° 101 mm
Celje
Cool
10°21° 108 mm
Kranj
Cool
9°21° 138 mm
Koper
Mild
16°24° 102 mm
Novo Mesto
Cool
10°21° 115 mm
Velenje
Cool
9°20° 116 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 September.
Where to Go in Slovenia in September
Julian Alps & Alpine Slovenia
Bled, Bohinj, Kranjska Gora, Triglav
Late autumn brings rapidly falling temperatures and the first significant snowfalls at higher elevations; lower valleys still enjoy pleasant daytime hiking but expect frosty mornings. Mountain refuges start to shut down for the season except for staffed weekends; unmaintained trails above tree line become icy and treacherous. Roadside viewpoints may be mist-swept, and thermal spas in nearby valleys (e.g., Dobrna) offer welcome warmth after brisk walks.
Soča Valley & Goriška Hills
Bovec, Kobarid, Tolmin, Nova Gorica, Goriška Brda
Winter brings frequent frosts and snow on the surrounding mountains while valley floors remain cooler but often snow-free; the contrast between snowy ridges and clear-soled river can be striking. Kayaking and rafting largely pause, but winter hiking and WWI history routes are accessible in milder spells. Good waterproof boots and insulated layers make short hikes comfortable, and the quieter season reveals intimate village life.
Slovenian Coast & Karst
Piran, Koper, Portorož, Škocjan Caves, Lipica
Winter’s chill can be damp rather than freezing along the coast, with frequent overcast skies and storms that make the sea restless-harbor walks and cave tours are the most reliable outdoor activities. Lipica’s horses are active and visible year-round, and cave temperatures remain steady and cool for a comfortable visit. Bring a waterproof jacket and sturdy shoes for muddy Karst trails.
Ljubljana & Central Slovenia
Ljubljana, Kamnik, Radovljica, Central Sava Valley
Winter’s arrival means cooler days and potential snow that dusts the castle and cloistered streets, turning Ljubljana into a tidy winter cityscape. Christmas markets and seasonal events draw visitors despite brisk temperatures; bring thermal layers and sturdy shoes for icy sidewalks. Daytime highs typically hover just above or slightly below freezing, so expect shorter daylight and an indoor-focused itinerary.
Northeast & Southeast Lowlands
Prekmurje, Ptuj, Murska Sobota, Dolenjska, Bela Krajina, Rogaška
Winter often settles in with prolonged frost and snow in the lowlands, though amounts are usually lower than in the Alps but can persist. Spas and museum visits become prime activities, and medieval Ptuj holds atmospheric winter markets. Roads in rural areas may be icy-winter tyres are recommended if driving-and layering is essential for outdoor exploration.
Events & Festivals in September
There are no major festivals or events in Slovenia during September to be aware of.
Planning a trip to Slovenia?
See how September compares with the rest of the year, then read the full guide.
