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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.

  • 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.

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Average dry days
21
Dry days
Average rainy days
9
Rainy days
Average snowy days
0
Snow days
Average temperatures
29°/15°
Temperatures
Average wind speed
15 km/h
Avg max wind
Average humidity
60 %
Avg humidity

Siena in September average weather

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Temperatures trend during September in Siena

See the weather trend as well as the moving average line
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September weather day by day

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Date Weather Temperatures Rain UV More
1 Sept. Sunny
Sunny
35° /19° 0 mm 9
2 Sept. Thundery outbreaks possible
Thundery outbreaks possible
31° /17° 4.5 mm 7
3 Sept. Patchy rain possible
Patchy rain possible
31° /17° 0.9 mm 7
4 Sept. Patchy rain possible
Patchy rain possible
31° /17° 2.3 mm 7
5 Sept. Patchy light rain with thunder
Patchy light rain with thunder
26° /17° 11.2 mm 6
6 Sept. Patchy rain possible
Patchy rain possible
27° /17° 0.1 mm 6
7 Sept. Patchy rain possible
Patchy rain possible
31° /15° 0 mm 7
8 Sept. Sunny
Sunny
28° /16° 21.1 mm 7
9 Sept. Sunny
Sunny
30° /15° 18.8 mm 7
10 Sept. Sunny
Sunny
30° /13° 0 mm 8
11 Sept. Sunny
Sunny
30° /15° 1.1 mm 7
12 Sept. Sunny
Sunny
28° /14° 11.8 mm 7
13 Sept. Partly cloudy
Partly cloudy
22° /11° 3.4 mm 6
14 Sept. Partly cloudy
Partly cloudy
25° /11° 0 mm 7
15 Sept. Partly cloudy
Partly cloudy
26° /12° 0 mm 7
16 Sept. Thundery outbreaks possible
Thundery outbreaks possible
26° /13° 0.2 mm 6
17 Sept. Sunny
Sunny
25° /14° 0.4 mm 6
18 Sept. Partly cloudy
Partly cloudy
23° /14° 0.2 mm 6
19 Sept. Mist
Mist
24° /13° 0.3 mm 5
20 Sept. Overcast
Overcast
23° /13° 0.5 mm 5
21 Sept. Patchy rain possible
Patchy rain possible
25° /13° 3.1 mm 6
22 Sept. Light rain shower
Light rain shower
24° /14° 5.7 mm 6
23 Sept. Light rain shower
Light rain shower
22° /12° 5 mm 5
24 Sept. Patchy rain possible
Patchy rain possible
22° /12° 1.4 mm 5
25 Sept. Partly cloudy
Partly cloudy
24° /11° 3.8 mm 6
26 Sept. Sunny
Sunny
26° /13° 0 mm 6
27 Sept. Sunny
Sunny
27° /14° 1 mm 7
28 Sept. Sunny
Sunny
24° /11° 0.1 mm 6
29 Sept. Sunny
Sunny
24° /10° 0 mm 6
30 Sept. Sunny
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?
During September, expect a variety of temperatures with highs around 29° and lows near 15°, suitable for diverse activities and preferences.
How much rainfall should be expected in Siena during September?
In September, Siena can expect light to moderate rainfall, totaling 40.7 mm across approximately 9 days. Occasional showers are possible, and planning ahead for them could be helpful.
What are the typical wind conditions in Siena during September?
The average wind speed in Siena during September is 15 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
    • 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

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Location coordinates Where is Siena?

Get accurate weather forecasts for Siena, located at latitude 43.318 and longitude 11.331. Stay updated with localized weather information tailored for Siena.

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