Siena
September
Weather in Siena for September 2025
Your guide to Siena weather in September - trends and predictions
In general, the average temperature in Siena at the beginning of September is 30.3 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 24.6 °C by the end of September.
The climate of Siena in September is notably wet, with an average of 14 rainy days, and a total of 96.9 mm of precipitation.
Is September a good time to visit Siena? check out the best time to travel to Siena page.
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Temperatures
Rain 🌧️
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16
Dry days
14
Rainy days
0
Snow days
26°/14°
Temperatures
16 km/h
Avg max wind
65 %
Avg humidity
Siena in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  35° | 2  31° | 3  31° | 4 31° | 5  26° | 6 27° | 7 31° |
| 8 28° | 9 30° | 10 30° | 11 30° | 12 28° | 13  22° | 14 25° |
| 15 26° | 16 26° | 17 25° | 18 23° | 19  24° | 20  23° | 21 25° |
| 22 24° | 23 22° | 24 22° | 25 24° | 26 26° | 27 27° | 28 24° |
| 29 24° | 30 25° |
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Temperatures trend during September in Siena
See the weather trend as well as the moving average line
September weather day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. | Sunny | 35° /19° | 0 mm | 9 | |
| 2 Sept. | Thundery outbreaks possible | 31° /17° | 4.5 mm | 7 | |
| 3 Sept. | Patchy rain possible | 31° /17° | 0.9 mm | 7 | |
| 4 Sept. | Patchy rain possible | 31° /17° | 2.3 mm | 7 | |
| 5 Sept. | Patchy light rain with thunder | 26° /17° | 11.2 mm | 6 | |
| 6 Sept. | Patchy rain possible | 27° /17° | 0.1 mm | 6 | |
| 7 Sept. | Patchy rain possible | 31° /15° | 0 mm | 7 | |
| 8 Sept. | Sunny | 28° /16° | 21.1 mm | 7 | |
| 9 Sept. | Sunny | 30° /15° | 18.8 mm | 7 | |
| 10 Sept. | Sunny | 30° /13° | 0 mm | 8 | |
| 11 Sept. | Sunny | 30° /15° | 1.1 mm | 7 | |
| 12 Sept. | Sunny | 28° /14° | 11.8 mm | 7 | |
| 13 Sept. | Partly cloudy | 22° /11° | 3.4 mm | 6 | |
| 14 Sept. | Partly cloudy | 25° /11° | 0 mm | 7 | |
| 15 Sept. | Partly cloudy | 26° /12° | 0 mm | 7 | |
| 16 Sept. | Thundery outbreaks possible | 26° /13° | 0.2 mm | 6 | |
| 17 Sept. | Sunny | 25° /14° | 0.4 mm | 6 | |
| 18 Sept. | Partly cloudy | 23° /14° | 0.2 mm | 6 | |
| 19 Sept. | Mist | 24° /13° | 0.3 mm | 5 | |
| 20 Sept. | Overcast | 23° /13° | 0.5 mm | 5 | |
| 21 Sept. | Patchy rain possible | 25° /13° | 3.1 mm | 6 | |
| 22 Sept. | Light rain shower | 24° /14° | 5.7 mm | 6 | |
| 23 Sept. | Light rain shower | 22° /12° | 5 mm | 5 | |
| 24 Sept. | Patchy rain possible | 22° /12° | 1.4 mm | 5 | |
| 25 Sept. | Partly cloudy | 24° /11° | 3.8 mm | 6 | |
| 26 Sept. | Sunny | 26° /13° | 0 mm | 6 | |
| 27 Sept. | Sunny | 27° /14° | 1 mm | 7 | |
| 28 Sept. | Sunny | 24° /11° | 0.1 mm | 6 | |
| 29 Sept. | Sunny | 24° /10° | 0 mm | 6 | |
| 30 Sept. | Sunny | 25° /10° | 0 mm | 7 | |
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Important Notice
Our weather forecast for Siena in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Siena forecast closer to your planned date for the most up-to-date weather information.
Siena in September - FAQ
What are the expected maximum and minimum temperatures in Siena during September?
Enjoy moderate daytime temperatures of up to 26° and cooler nights around 14°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Siena during September?
Moderate rainfall is anticipated in Siena during September, with a total of 96.9 mm spread over approximately 14 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Siena during September?
The average wind speed in Siena during September is 16 km/h, suggesting breezy to windy conditions, depending on your activities.
What to pack to Siena in September?
As you prepare for your trip to Siena in September, it's important to consider the typical weather patterns for the time of year. Below is a carefully tailored packing list to ensure that your time in Siena, during September, is comfortable and enjoyable, regardless of the weather conditions.
- Clothing
- Lightweight Clothing: T-shirts, blouses, shorts, skirts
- Rain Gear: Lightweight, waterproof clothing
- Footwear
- Waterproof Shoes
- Accessories
- Sunglasses: For sun protection
- Sun Hats: Wide-brimmed hats for sun protection in warm weather
- Scarves: To protect you from the cold wind
- Gloves/Mittens: Essential for cold weather
- Warm Hats: Warm hats for insulation in cold weather
- Umbrellas/Raincoats: For rainy days
- Personal Items
- Sunscreen: High SPF for sunny destinations
- Lip Balm with SPF: To protect against chapped lips
September rainfall patterns in Siena
Explore the daily rainfall trends and prepare for Sienas September weather 💧
UV exposure in Siena during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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