Siena · AutumnMonth summary
Siena weather in September
✅ Good
🌡️ Temperature min / max
59°F – 79°F
🌧 Rainy days
28% of days
☀️ Sunshine
11.7h per day on average
🌊 🌊 Season
Autumn
⭐ ⭐ Weather score
8.3/10
📅 📅 Best month
June (9.0/10)
Quick decision
Should you visit Siena in September?
✅ Good
✅ Yes if: you want good weather with lower prices than peak season.
❌ No if: you need guaranteed perfect weather — some mixed days are possible.
Our take: Favourable conditions in September (8.3/10). June scores higher but the gap is small.
By trip type
Siena in September by trip type
- 🏙️ 🏙️ City break / culture : ✅ Good
- 🚶 🚶 Outdoor activities : ✅ Good
- 🏖️ Beach / swimming : ✅ Good
- 💰 💰 Budget : 💸 Peak season
Local context
What to expect in September
Autumn in Siena is often underrated: 26°F, golden light and declining crowds. An interesting window. Expect rain on 28% of days — a light raincoat in the bag is recommended. A good balance between weather and crowds, even if June (9.0/10) remains theoretically better.
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All months for Siena
Annual table
Month-by-month comparison
| Month | Min °F | Max °F | Rain % | Precip in | Sun h/d | Score |
|---|---|---|---|---|---|---|
| 🌫️ January | 36°F | 50°F | 29% | 0.1in | 7.4h | 4.8/10 |
| ⛅ February | 37°F | 55°F | 33% | 0.1in | 8.8h | 5.7/10 |
| ⛅ March | 39°F | 59°F | 30% | 0.1in | 10.8h | 7.0/10 |
| 🌤️ April | 45°F | 66°F | 32% | 0.1in | 12.2h | 7.4/10 |
| 🌤️ May | 52°F | 72°F | 42% | 0.1in | 12.9h | 7.7/10 |
| ☀️ June | 61°F | 84°F | 22% | 0.1in | 14.1h | 9.0/10 |
| ☀️ July | 66°F | 90°F | 17% | 0.0in | 14.3h | 8.5/10 |
| ☀️ August | 66°F | 90°F | 19% | 0.0in | 13.0h | 8.2/10 |
| 🌤️ September | 59°F | 79°F | 28% | 0.1in | 11.7h | 8.3/10 |
| 🌤️ October | 52°F | 70°F | 27% | 0.1in | 9.8h | 7.5/10 |
| ⛅ November | 43°F | 59°F | 39% | 0.1in | 8.0h | 5.6/10 |
| 🌫️ December | 37°F | 52°F | 34% | 0.1in | 7.0h | 4.6/10 |
Ideal
Fair
Challenging climate
◀ Current month · Source Open-Meteo · 10 years
📊 Data source
Data based on 10 years of ERA5 records via Open-Meteo, with ECMWF seasonal adjustment. In September, Siena averages 79°F, 28% rainy days and 11.7h of sunshine per day. Overall weather score: 8.3/10.
See methodology →
Comparison
September vs June (best month)
The best month is June (score 9.0/10). Difference:
- 🌡️ Max temperature : +3°F
- 🌧 Rainy days : -6%
- ☀️ Sunshine : +2.4h/day
FAQ
FAQ — Siena in September
Is September a good time to visit Siena?
September is an excellent time to visit Siena (score 8.3/10). With 79°F, 11.7h of sunshine and 28% rain, conditions are very favourable.
What to do in Siena in September?
With 79°F and 11.7h of sunshine, all outdoor activities are possible: hiking, sightseeing and terraces.
Accommodation
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