Ljubljana in September
In September, Ljubljana averages 21°C (70°F) during the day and 11°C (53°F) at night, with around 12 days of rain (143 mm total).
High seasonConditions are comfortable for sightseeing without being sweltering. Plan for unsettled weather and bring rain gear.
September offers comfortable temperatures in Ljubljana, with some rain to plan around.
How September compares to the rest of the year in Ljubljana
September is in the middle of the year for warmth in Ljubljana (4th of 12) and moderately rainy compared to the rest of the year (4th of 12). Daytime temperature runs 5°C above the annual average (16°C). September runs 5°C cooler than August (26°C) and cools 5°C in October (17°C).
September sunrise & sunset in Ljubljana
Times shown for Ljubljana local time (Europe/Ljubljana), calculated for the 15th of September. They shift by a few minutes day to day across the month.
Photography light in Ljubljana — September
Golden-hour and blue-hour windows for the 15th of September, in Ljubljana's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).
📅 When to book — Ljubljana in September
Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on September's tier (High season) and Ljubljana's popularity.
Crowds & pricing — September in Ljubljana
This is a busy month in Ljubljana — not the absolute peak, but tourist numbers are clearly elevated. You'll feel it at headline attractions on weekends and in the historic centre, though side streets and lesser-known sights stay manageable. Prices are above off-season but not at their summit. A good week for first-time visitors who want everything open without the worst of the crush.
Why this tier: excellent tourism weather
Sun & mosquito risk — September in Ljubljana
UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.
Ljubljana in other months
| Month | Avg high | Avg low | Rainfall | Rain days | Snow days |
|---|---|---|---|---|---|
| January | 5°C / 41°F | -3°C / 27°F | 84 mm | 9 | — |
| February | 8°C / 46°F | -2°C / 29°F | 100 mm | 10 | — |
| March | 12°C / 53°F | 1°C / 33°F | 64 mm | 9 | — |
| April | 16°C / 61°F | 5°C / 40°F | 84 mm | 10 | — |
| May | 19°C / 67°F | 9°C / 48°F | 134 mm | 16 | — |
| June | 25°C / 77°F | 14°C / 57°F | 91 mm | 12 | — |
| July | 27°C / 81°F | 16°C / 61°F | 101 mm | 12 | — |
| August | 26°C / 80°F | 16°C / 60°F | 100 mm | 10 | — |
| September | 21°C / 70°F | 11°C / 53°F | 143 mm | 12 | — |
| October | 17°C / 62°F | 7°C / 45°F | 110 mm | 10 | — |
| November | 10°C / 51°F | 3°C / 38°F | 140 mm | 11 | — |
| December | 6°C / 42°F | -1°C / 30°F | 98 mm | 9 | — |
Other cities with similar September weather
🌍 See the full ranked list of climate twins for Ljubljana in September →
Frequently asked questions
How hot is Ljubljana in September?
In September, Ljubljana averages a high of 21°C (70°F) and a low of 11°C (53°F) — generally mild and pleasant.
Does it rain a lot in Ljubljana in September?
September can be fairly wet in Ljubljana, with about 12 rainy days on average.
Is September a good time to visit Ljubljana?
September is mild and pleasant. It suits travelers who are comfortable with mild and pleasant weather; check the month-by-month ranking to compare it against the rest of the year.
What should I pack for Ljubljana in September?
Pack light layers for warm days and cooler evenings, plus a compact umbrella or rain jacket. See the full September packing list for Ljubljana for a complete, climate-based checklist.
Check the live 10-day forecast and sunrise/sunset.