Weather in Siena for September 2025
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.
Siena sees moderate rainfall in September, averaging 9 rainy days.
Is September a good time to visit Siena? check out the best time to travel to Siena page.
- New! Chat with our AI weatherman - it’s amazing and free.
Siena in September average weather
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° |
You can click on date
Temperatures trend during September in Siena
September weather day by day
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 | |
Next |
Siena in September - FAQ
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
- Sandals/Flip-flops: Comfortable for warm climates
- Accessories
- Sunglasses: For sun protection
- Sun Hats: Wide-brimmed hats for sun protection in warm 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
UV exposure in Siena during September
Quick links
Get accurate weather forecasts for Siena, located at latitude 43.318 and longitude 11.331. Stay updated with localized weather information tailored for Siena.