SeasonMapSan Marino weather in September
San Marino
September in San Marino: nice, rainy, with clean air — an excellent time to visit.
#4 of 12 months in San Marino · #395 of 1383 destinations to visit in September · comfort 87/100 (tier A)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on San Marino in September
Notes from nearby Bologna (108 km away)
San Marino doesn't have its own notes for September yet — these are about Bologna, close enough to share the season.
Bologna's forum is candid that September splits in two — the first half still runs warm and beach-worthy, the second turns genuinely unpredictable, with one regular describing a 29°C day followed two days later by 19°C. Regulars call nights in September noticeably cooler than June's, worth a real layer rather than just a light one.
Add your own note from San Marino's card on the map.
San Marino climate normals — September
| Daytime high | 22°C / 71°F | 😎 nice |
|---|---|---|
| Nighttime low | 13°C / 55°F | |
| Feels like (high) | 21°C / 70°F | |
| Sea temperature | 25°C / 77°F | 😎 warm sea |
| Rainfall | 95 mm / 3.7 in | 🌧 rainy |
| Rainy days | 9 days | |
| Humidity | 73% | 💧 humid |
| Dew point | 12°C / 53°F | |
| Sunshine | 10.1 h/day | |
| Daylight | 12.5 h | |
| Wind | 15 km/h / 9 mph | |
| Air quality (US AQI) | 47 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in San Marino 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.
Peak crowdsFeast of Saint Marinus, San Marino motorcycle Grand Prix, school holidays in 3 of the markets that fill it(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for San Marino'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 weatherSan Marino's weather peaks June–August.
Best weatherFair weatherToughest weather
What's on in San Marino in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Holiday
Feast of Saint Marinus
3 SepMajor festivalClosuresThe national day on 3 September marks the founding of the republic in 301, with a procession, a torchlit evening and everything official shut. It is the busiest date in the calendar. Source ↗
- Festival
San Marino motorcycle Grand Prix
5–20 Sep · usuallyMotorsport weekendCrowdedBook earlyThe race is run at Misano on the coast below, but the beds are taken across the whole province including up here, and the roads on the Sunday are motorcycles end to end. Source ↗
Nearby, and something's on
Within 300 km of San Marino — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is San Marino?
San Marino in September — FAQ
- Is September a good time to visit San Marino?
- September in San Marino: nice, rainy, with clean air — an excellent time to visit. It ranks #4 of 12 months for San Marino on SeasonMap's comfort score (87/100).
- What is the weather like in San Marino in September?
- In September, San Marino averages a daily high of 21.5°C and a low of 12.7°C, with about 95.1 mm of rain over roughly 9.4 rainy days.
- What is the air quality in San Marino in September?
- San Marino has a mean US Air Quality Index of about 47 in September.
Other months in San Marino
Compare San Marino in September
Warmer or cooler than San Marino in September
Similar destinations in Southern Europe — September
Within 300 km: Bologna's Bologna Estate on 1 Jun – 15 Sep, and Siena's Chianti and Brunello harvest around 5 Sep – 15 Oct.