Climate and monthly weather forecastSiena, Italy
Climate and monthly weather forecast
The climate of Siena
Positioned geographically in the heart of Italy, Siena conveys a blend of various weather patterns. As per the Köppen climate classification, it falls under the Cfa category, identified generally as a humid subtropical climate without a dry season. The year-round weather indicates notable variations following the shift of seasons.Throughout the year, temperature swings from a low of 1.9°C (35.4°F) in winter to a high of 30.3°C (86.5°F) in summer. Humidity fluctuates relatively less, maintaining a level from 63% in summer to 85% in winter. Rainfall pattern in Siena is sporadic and can take place in any month, with November being the wettest month with a substantial 50mm (1.97") of precipitation. The city also experiences occasional snowfall, peaking in February with about 20mm (0.79") accumulation.
Daylight hours peak at 15.4 hours in June, then taper off to a minimum of 9 hours in December. Sunshine is abundant in Siena, with up to 23.9 days in July and August. The wind speed varies moderately from 7.1 to 10.8 Kph, with February marked as the breeziest month.
The best time to visit Siena
For an optimal experience in Siena, consider planning visits from late May to early September. During this period, temperatures average between a comfortable 20.4°C (68.7°F) to 30.3°C (86.5°F), coupled with the lowest humidity level of the year. June offers the longest daylight of up to 15.4 hours, enhancing sightseeing opportunities. Rainfall also reaches its lowest point in August, with approximately 14mm (0.55") over 6 days.The worst time to visit Siena
Due to the plunge in temperatures, the cold months from December to February might not be an ideal time to visit Siena. Average low temperatures hover from 1.9°C (35.4°F) to 2.2°C (36°F), and while snowfall is minimal, it is prevalent during these months. This period also sees fewer sunshine days and reduced daylight time, which might restrict sightseeing activities.Spring weather in Siena
Spring in Siena, stretching from March to May, is a season of gradual warming. Temperatures rise steadily from 13.3°C (55.9°F) to 20.4°C (68.7°F), while the number of sunshine days increases to peak at 16.4 in May. However, the onset of spring also ushers in increased rainfall with 39mm (1.54") precipitation in May.Summer weather in Siena
Summer, running from June to August, is the warmest season in Siena. Daytime temperatures soar to an average high of 30.3°C (86.5°F), while nights cool down to an inviting 16.3°C (61.3°F). It also earns the distinction of being the driest season, with August seeing only 14mm (0.55") rainfall.Autumn weather in Siena
Autumn signals a shift towards cooler temperatures, with the thermometer reading from 24.5°C (76.1°F) to 13.6°C (56.5°F) from September to November. Rainfall escalates during this period, culminating in November with a high of 50mm (1.97"), the highest precipitation level of the year.Winter weather in Siena
Respecting the regular weather patterns, Siena's winter, occurring in December through February, brings a chill in the air. With average temperatures ranging from 1.9°C (35.4°F) to 4.1°C (39.4°F), and the probability of 20mm (0.79") snowfall in February, it marks the coldest months. Alongside, daylight hours shrink to 9 hours, and sunshine days reduce to as low as 14.7 in December.Weather in January
January in Siena, Italy, introduces the populace to the start of the calendar year with noticeably chilly temperatures. Despite the cold weather, the winter beauty of Siena captivates many tourists with frosted landscapes and quiet streets. Weather in January »Weather in February
Moving into February, a notable rise in temperature and snowfall can be observed in Siena, Italy. The weather transitions from the bitter cold of January, making the city a more visitors-friendly destination. During this month, snowfall averages at 20mm (0.79") covering 1.4 days, making it ideal for winter sports enthusiasts. Weather in February »Weather in March
March brings the charm of early spring to Siena, Italy, warming up the city after the snow-filled February. The climate gradually begins to intensify, transforming the wintery landscapes into a scenery filled with blossoming flowers and lush greenery. Weather in March »Weather in April
April in Siena, Italy, presents an increase in temperature and rainfall, marking the arrival of spring in full bloom. With the complete dissipation of snow, the city flourishes under the mild warmth of the spring sun. Residents and tourists revel in the extended daylight hours of 13.4 hours per day, ushering in a period of outdoor festivities and cultural events. Weather in April »Weather in May
The month of May in Siena, Italy, showcases the city in the glory of late spring with rising temperatures and extended sunshine hours. The city comes alive with blossoming flora, making it an immensely attractive period for tourists. Weather in May »Weather in June
June heralds the onset of summer in Siena, Italy, manifesting as a significant increase in temperature compared to the preceding spring months. The weather conditions during this period encourage locals and visitors alike to engage in outdoor pursuits. Weather in June »Weather in July
July in Siena, Italy, typically constitutes the heart of the summer, characterized by high temperatures and reduced rainfall. Seasoned with extensive daylight hours and minimum cloud coverage, the city offers its warmest welcome to tourists. Weather in July »Weather in August
The month of August represents the climax of the Siena summer, Italy, maintaining the heat of July but with slightly more humid conditions. The weather, swaying between balmy and hot, ushers in a festive summer spirit, making historic city exploration an absolute delight. Weather in August »Weather in September
Entering September, Siena, Italy, begins to witness the onset of autumn, characterized by occasional rainfall and a marked decrease in temperature. The weather in September boasts a delightful blend of sun and rain, creating a picturesque backdrop. Weather in September »Weather in October
October in Siena, Italy, is a symbol of autumn's full swing, characterized by cooler temperatures, vibrant landscapes, and occasional showers. The dropping temperatures create a comfortable climate, providing relief from the summer heat. Weather in October »Weather in November
November in Siena, Italy, showcases the subtle transition from autumn to winter, with a marked drop in temperature compared to October. The city experiences higher rainfall during this period, enhancing the vibrancy of the landscape. Weather in November »Weather in December
December in Siena, Italy, marks the arrival of winter with cold temperatures, rare snowfall, and minimal sunshine. The city decks itself up for the holiday season, adding a unique charm to the chilly weather. With a gradual drop in temperature to a low of 3.1°C (37.6°F), winter coats become indispensable. Weather in December »Updated: Jan 30, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Siena's temperature records reveal January as the coldest month, marked by average highs of 8.5°C (47.3°F) and lows of 1.9°C (35.4°F).
In Siena, during the entire year, the rain falls for 123.6 days and collects up to 363mm (14.29") of precipitation.
January through March and December are months with snowfall in Siena.
Throughout the year, in Siena, Italy, there are 3.6 snowfall days, and 48mm (1.89") of snow is accumulated.
January has the least sunshine of the year in Siena, with an average of 5.3h of sunshine.
The months with the lowest UV index are January and December, with an average maximum UV index of 2.
The month with the most snowfall is February, when snow falls for 1.4 days and typically aggregates up to 20mm (0.79") of snow.
In Siena, snow does not fall in April through November.
With an average of 15h and 18min of daylight, June has the longest days of the year.
June through August, with an average maximum UV index of 6, are months with the highest UV index.
July and August, with an average of 11.9h of sunshine, are months with the most sunshine.
Siena, Italy, reaches its average highest temperatures in August, measuring 30.3°C (86.5°F) at the peak and 16.3°C (61.3°F) at the lowest.
August is the least humid month, with an average relative humidity of 63%.
The month with the least rainfall in Siena is August, when the rain falls for 5.8 days and typically collects 14mm (0.55") of precipitation.
On Sunday, 27. October 2024, at 03:00, Daylight Saving Time ends in Siena, Italy, and the time zone changes from CEST to CET. The next Daylight Saving Time starts on Sunday, 30. March 2025, at 02:00, and the time zone reverts from CET to CEST.
With an average relative humidity of 85%, November is the most humid month.
The month with the most rainfall in Siena is November, when the rain falls for 12.2 days and typically aggregates up to 50mm (1.97") of precipitation.
December has the shortest days of the year in Siena, with an average of 9h and 0min of daylight.
Average temperature
Siena, Italy
The warmest month (with the highest average high temperature) is August (30.3°C).
The month with the lowest average high temperature is January (8.5°C).
The month with the highest average low temperature is August (16.3°C).
The coldest month (with the lowest average low temperature) is January (1.9°C).
Average pressure
Siena, Italy
- Average pressure in January:
1016.3mbar - Average pressure in February:
1014.4mbar - Average pressure in March:
1014.4mbar - Average pressure in April:
1014mbar - Average pressure in May:
1014mbar - Average pressure in June:
1014mbar
- Average pressure in July:
1013.5mbar - Average pressure in August:
1014.3mbar - Average pressure in September:
1015.5mbar - Average pressure in October:
1016.4mbar - Average pressure in November:
1014.3mbar - Average pressure in December:
1018.4mbar
The month with the highest atmospheric pressure is December (1018.4mbar).
The month with the lowest atmospheric pressure is July (1013.5mbar).
Average wind speed
Siena, Italy
- Average wind speed in January:
9.3km/h - Average wind speed in February:
10.8km/h - Average wind speed in March:
10.8km/h - Average wind speed in April:
8.7km/h - Average wind speed in May:
8.1km/h - Average wind speed in June:
7.1km/h
- Average wind speed in July:
7.3km/h - Average wind speed in August:
7.2km/h - Average wind speed in September:
8km/h - Average wind speed in October:
8.2km/h - Average wind speed in November:
8.9km/h - Average wind speed in December:
8.3km/h
The windiest months (with the highest average wind speed) are February and March (10.8km/h).
The calmest month (with the lowest average wind speed) is June (7.1km/h).
Average humidity
Siena, Italy
The month with the highest relative humidity is November (85%).
The month with the lowest relative humidity is August (63%).
Average rainfall
Siena, Italy
The wettest month (with the highest rainfall) is November (50mm).
The driest month (with the least rainfall) is August (14mm).
Average rainfall days
Siena, Italy
- Average rainfall days in January:
11.6 days - Average rainfall days in February:
11.3 days - Average rainfall days in March:
12.3 days - Average rainfall days in April:
12.2 days - Average rainfall days in May:
13.5 days - Average rainfall days in June:
8.6 days
- Average rainfall days in July:
6.1 days - Average rainfall days in August:
5.8 days - Average rainfall days in September:
9.4 days - Average rainfall days in October:
9.8 days - Average rainfall days in November:
12.2 days - Average rainfall days in December:
10.8 days
The month with the highest number of rainy days is May (13.5 days).
The month with the least rainy days is August (5.8 days).
Average snowfall
Siena, Italy
The month with the highest snowfall is February (20mm).
The months with the least snowfall are April, May, June, July, August, September, October and November (0mm).
Average snowfall days
Siena, Italy
- Average snowfall days in January:
0.8 days - Average snowfall days in February:
1.4 days - Average snowfall days in March:
0.8 days - Average snowfall days in April:
0 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0 days - Average snowfall days in November:
0.1 days - Average snowfall days in December:
0.5 days
The month with the highest number of snowfall days is February (1.4 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight / Average sunshine
Siena, Italy
- Average daylight in January:
9h and 24min - Average daylight in February:
10h and 30min - Average daylight in March:
11h and 54min - Average daylight in April:
13h and 24min - Average daylight in May:
14h and 42min - Average daylight in June:
15h and 18min
- Average daylight in July:
15h and 0min - Average daylight in August:
13h and 54min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 0min - Average daylight in November:
9h and 42min - Average daylight in December:
9h and 0min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in January:
5h and 18min - Average sunshine in February:
5h and 30min - Average sunshine in March:
7h and 42min - Average sunshine in April:
9h and 54min - Average sunshine in May:
10h and 24min - Average sunshine in June:
11h and 30min
- Average sunshine in July:
11h and 54min - Average sunshine in August:
11h and 54min - Average sunshine in September:
10h and 24min - Average sunshine in October:
6h and 24min - Average sunshine in November:
5h and 24min - Average sunshine in December:
5h and 36min
The months with the most sunshine are July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 5h and 18min).
Average sunshine days
Siena, Italy
- Average sunshine days in January:
16.6 days - Average sunshine days in February:
14.6 days - Average sunshine days in March:
17.4 days - Average sunshine days in April:
16.4 days - Average sunshine days in May:
16.2 days - Average sunshine days in June:
19.3 days
- Average sunshine days in July:
23.3 days - Average sunshine days in August:
23.9 days - Average sunshine days in September:
18.9 days - Average sunshine days in October:
19.2 days - Average sunshine days in November:
14.7 days - Average sunshine days in December:
16.8 days
The month with the most sunshine days is August (23.9 days).
The month with the least sunshine days is February (14.6 days).
Average UV index
Siena, Italy
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover
Siena, Italy
The months with the most cloud cover are January, February and November (Cloud cover 44).
The month with the least cloud cover is August (Cloud cover 13).
Average visibility
Siena, Italy
The months with the highest visibility are February, March, April, May, June, July, August, September and December (9km).
The months with the lowest visibility are January, October and November (8km).
