August 17 is statistically one of the best days of the year in Siena. With minimal rain risk (11%) and pleasant highs of 31°C, it's ideal for outdoor adventures. Siena is currently in its most popular travel window, meaning vibrant crowds and premium pricing.
View the full calendar
Essential Travel Info for Siena
Currency
EUR
€ Euro
Language
Italian
+1 more
Driving
Right side
Safety
High Safety
GPI: 1.643
Siena Weather Forecast for August 17
"Warm & Sunny. Expect average highs of 30.6°C. 11% chance of rain."
What to Wear in Siena in August
Based on historical data for August 17, Siena typically experiences temperatures between 18.3°C and 30.6°C. We recommend packing t-shirt, light clothing, layers (onion system) to stay comfortable. Trends suggest it will stay mostly dry (11% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for Siena
Smart Suitcase
- T-Shirt
- Light Clothing
- Layers (Onion System)
Average High
30.6°C
Daytime Peak
Average Low
18.3°C
Nighttime Low
Feels Like
34°C
🔥 Feels warmer
Rain Chance
11%
Avg 0.4mm if it rains
Cloud Cover
32%
Overcast
Pressure
1014.1 hPa
Low volatility
Siena Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 100% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
05:00 - 10:00
16:00 - 19:00
Type I-II
🔴 15 min to burn
Type III-IV
🟡 23 min to burn
Type V-VI
🟢 38 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
21.9°C
Humid/Sticky
Heat Index
34°C
Feels hotter
🙂 Best outdoor time:
Early morning (6-9 AM) or evening (after 6 PM)
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in Italy
Flight Traffic
High
100/100 pressure index
Health Advisory
Required
1 vaccine • View Details →
Landing Slots
~64
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Siena
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:23
☀️ Noon
12:20
🌇 Sunset
19:17
⏱️ Daylight
13h 54m
Wind Speed
12.8 km/h
Gentle breeze
Sunshine
12.2 hrs
Direct Sun (Cloud-free)
Humidity
60%
Slightly humid
Travel Intelligence
Exclusive flight analytics & health data for Siena
Smart Flight Estimator
Airport-to-Airport Logistics
unlock smart flight estimates
Add your home location in settings to see airport details.
Travel Health & Safety in Siena
Travel Comfort Index
Real-time tourism conditions
Weather Quality
☀️ Excellent
Tourist Crowds
🔴 Very Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Stable conditions. Low risk of headaches.
Weather unlikely to affect joint pain.
Moderate fish activity expected.
Air quality is acceptable. Sensitive individuals should limit prolonged outdoor exertion.
Regional Safety Profile
Seismic Activity
Moderate seismic activity. Occasional tremors possible.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, Siena on August 17 averages 30.6°C with a 11% precipitation probability. Wedding/Outdoor Event Score: 100/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Siena Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Compare Other Cities
Same date (August 17) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Siena Worth Visiting on August 17?
Planning a trip to Siena on August 17? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year typically offers vibrant summer conditions averaging 30.6°C with a 11% historical precipitation risk.
✈️ Travel Logistics: Approximately 64 landing slots available daily during this period, indicating manageable crowd levels.
💉 Health Advisory: 7 vaccinations are recommended for Italy, including COVID-19.
📊 Historical Extremes: The hottest August 17 recorded in the last 30 years saw temperatures hit 34.8°C in 2017, while the coldest dropped to 17.3°C in 2016.