Siena Weather in August
August in Siena brings very high temperatures, with daytime highs of 31°C (88°F) and nights around 18°C (64°F). Expect around 41 mm (1.6 in) of rainfall during the month.
Rainfall in Siena in August
This month experiences about 8 days of rain according to historical data, averaging 41 mm (1.6 in). Rain this month is fairly typical, a standard mix of wet and dry days with no particularly heavy or persistent showers.
Temperature in Siena in August
Expect highs of 31°C (88°F) in Siena in August, with nights dropping to around 18°C (64°F). The hottest part of the day is usually in the afternoon, so lighter clothing can help you stay comfortable. Nights cool down to 18°C (64°F), so a light jacket or extra layer is useful once the sun goes down. On the plus side, the cooler nights make for comfortable sleeping conditions. Note that these temperatures are average, but some days may be hotter. Dress in cool, breathable fabrics to stay comfortable in the heat.
Sunshine in Siena in August
The month enjoys around 320 hours of sunshine, creating mostly sunny days with good weather conditions.Should you favor a climate that's both dry and comfortably warm, May, June and September typically offer the most agreeable circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Italy, check out our Siena's climate page.
Siena Temperature in August
Min Temperature
18°C (64°F)
Max Temperature
31°C (88°F)
Chance of Rain
27%
Precipitation
41 mm (1.6 in)
Rainy days
8 days
Sunshine
320 hours
Percentage Sunshine
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Siena typically stay consistent throughout August, with daily highs averaging around 31°C (88°F). Nights are pleasant, with lows typically ranging from 16°C (61°F) to 19°C (66°F).
Average temperatures in August
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in August
Historical weather for Siena in August
Browse day-by-day weather records for Siena spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Siena historical weather extremes in August
Based on weather observations in Siena between 1976 and 2025, these are the recorded extremes during August.
- The hottest August day on record in Siena reached 40°C (104°F) (August 3, 2017).
- The lowest daytime temperature in August was 19°C (66°F), recorded on August 21, 2005.
- Nighttime temperatures dropped to 9°C (48°F) on August 31, 2010, marking the coldest August night on record.
Best Places in Italy in August
Find out more about the weather in Italy and which places have the best travel conditions in this month. See all of Italy in August →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Siena in August
Warm weather calls for comfortable, breathable clothing in August. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). Rain is likely on several days, so bring a good rain jacket. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.What To Do in Siena in August
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Italy, check out our Siena's climate page.
See the full Siena climate overview or explore weather in Italy.
