December weather forecastSiena, Italy
December
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. Although the average snowfall registers at 5mm (0.2") over a mere 0.5 days, the onset of winter becomes apparent. The dwindling daylight hours and a slight increase in wind speed make it a perfect time for indoor activities and embracing the cosy Italian cafe culture.Temperature
With the onset of December, the average high-temperature subtly recedes from November's refreshing 13.6°C (56.5°F) to a chilly 9.5°C (49.1°F). Siena, during the nights of December, experiences an average temperature drop to a wintry 3.1°C (37.6°F).Humidity
The average relative humidity in December is 82%.Rainfall
In Siena, in December, it is raining for 10.8 days, with typically 34mm (1.34") of accumulated precipitation. Throughout the year, there are 123.6 rainfall days, and 363mm (14.29") of precipitation is accumulated.Snowfall
January through March and December are months with snowfall in Siena. December is the first month it typically snows. Throughout December, in the average 0.5 snowfall days, it receives 5mm (0.2") of snow. In Siena, during the entire year, snow falls for 3.6 days and aggregates up to 48mm (1.89") of snow.Daylight
With an average of 9h and 0min of daylight, December has the shortest days of the year in Siena.On the first day of December in Siena, sunrise is at 07:27 and sunset at 16:40. On the last day of the month, sunrise is at 07:46 and sunset at 16:48 CET.
Sunshine
The average sunshine in December in Siena is 5.6h.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.Note: In December, a daily maximum UV index of 2 leads to the following instructions:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Siena, Italy
- Average high temperature in December: 9.5°C
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).
- Average low temperature in December: 3.1°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 in December
Siena, Italy
- 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 in December
Siena, Italy
- 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 in December
Siena, Italy
- Average humidity in December: 82%
The month with the highest relative humidity is November (85%).
The month with the lowest relative humidity is August (63%).
Average rainfall in December
Siena, Italy
- Average rainfall in December: 34mm
The wettest month (with the highest rainfall) is November (50mm).
The driest month (with the least rainfall) is August (14mm).
Average rainfall days in December
Siena, Italy
- 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 in December
Siena, Italy
- Average snowfall in December: 5mm
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 in December
Siena, Italy
- 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 in December /
Average sunshine in December
Siena, Italy
- 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 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 in December
Siena, Italy
- 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 in December
Siena, Italy
- Average UV index in December: 2
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 in December
Siena, Italy
- Average cloud cover in December: 41
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 in December
Siena, Italy
- Average visibility in December: 9km
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).
