SeasonMapPiran weather in September
Slovenia
September in Piran: warm, soaked, with clean air — fine if you can take 11 rainy days.
#4 of 12 months in Piran · #613 of 1383 destinations to visit in September · comfort 82/100 (tier A)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Piran in September
Notes from nearby Venice (97 km away)
Piran doesn't have its own notes for September yet — these are about Venice, close enough to share the season.
Venice regulars on the forum rate September highly: pleasant enough for outdoor dinners without daytime sightseeing turning unpleasant, occasional rain but rarely the kind of flooding (acqua alta) that shows up in the winter months.
Add your own note from Piran's card on the map.
Piran climate normals — September
| Daytime high | 25°C / 77°F | 🌤 warm |
|---|---|---|
| Nighttime low | 20°C / 67°F | |
| Feels like (high) | 27°C / 81°F | |
| Sea temperature | 24°C / 75°F | 🙂 pleasant |
| Rainfall | 173 mm / 6.8 in | ⛈ soaked |
| Rainy days | 11 days | |
| Humidity | 71% | 💧 humid |
| Dew point | 14°C / 57°F | |
| Sunshine | 9.8 h/day | |
| Daylight | 12.5 h | |
| Wind | 15 km/h / 9 mph | |
| Air quality (US AQI) | 44 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Piran in September
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
BusyDay-tripper hours, school holidays in 3 of the markets that fill it(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Piran's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherPiran's weather peaks June–August, best around July.
Best weatherFair weatherToughest weather
What's on in Piran in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Season
Secovlje salt harvest
23 Apr – 15 Sep · usuallyThe salt pans south of town are still worked by hand from St George's Day through the summer, raked into white ridges on the same beds used for six hundred years. Out of season it is a birdwatching marsh instead. Source ↗
- Season
Day-tripper hours
15 May – 20 Sep · usuallyDay-tripper crushCrowdedCars stop at the Fornace car park and everyone arrives on the shuttle, so the old town fills between about ten and five and empties completely after. Stay the night and Tartini Square is yours. Source ↗
- Season
Swimming season
15 Jun – 25 Sep · usuallySea warm enoughThe northern Adriatic is shallow here, so it warms early and cools early; you swim off concrete platforms rather than sand. September water is still fine and the town is half as busy. Source ↗
- Festival
Tartini Festival
20 Aug – 5 SepMajor festivalA fortnight of chamber and baroque music for the violinist born on the square, played in the church and the Venetian halls rather than a concert venue. Late August into the first days of September. Source ↗
Nearby, and something's on
Within 300 km of Piran — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Piran?
Piran in September — FAQ
- Is September a good time to visit Piran?
- September in Piran: warm, soaked, with clean air — fine if you can take 11 rainy days. It ranks #4 of 12 months for Piran on SeasonMap's comfort score (82/100).
- What is the weather like in Piran in September?
- In September, Piran averages a daily high of 25°C and a low of 19.7°C, with about 172.8 mm of rain over roughly 10.9 rainy days.
- What is the air quality in Piran in September?
- Piran has a mean US Air Quality Index of about 44 in September.
Other months in Piran
Compare Piran in September
Warmer or cooler than Piran in September
Similar destinations in Central Europe — September
Within 300 km: Ljubljana's Open Kitchen food market around 15 Mar – 31 Oct, and Venice's Biennale on 9 May – 22 Nov.