Ljubljana weather in September
September in Ljubljana: nice, rainy, with clean air — an excellent time to visit.
#3 of 12 months in Ljubljana · #225 of 604 destinations to visit in September · comfort 84/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Ljubljana climate normals — September
| Daytime high | 21°C / 70°F | 😎 nice |
|---|---|---|
| Nighttime low | 13°C / 55°F | |
| Feels like (high) | 21°C / 70°F | |
| Rainfall | 122 mm / 4.8 in | 🌧 rainy |
| Rainy days | 11 days | |
| Humidity | 80% | 💦 very humid |
| Dew point | 13°C / 56°F | |
| Sunshine | 9.2 h/day | |
| Daylight | 12.5 h | |
| Wind | 11 km/h / 7 mph | |
| Air quality (US AQI) | 42 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Where is Ljubljana?
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Ljubljana in September — FAQ
- Is September a good time to visit Ljubljana?
- September in Ljubljana: nice, rainy, with clean air — an excellent time to visit. It ranks #3 of 12 months for Ljubljana on SeasonMap's comfort score (84/100).
- What is the weather like in Ljubljana in September?
- In September, Ljubljana averages a daily high of 21.3°C and a low of 12.6°C, with about 122.2 mm of rain over roughly 11.2 rainy days.
- What is the air quality in Ljubljana in September?
- Ljubljana has a mean US Air Quality Index of about 42 in September.