Last updated: March 24, 2025
Experience the charm of Siena, Italy, in December, where the landscape transforms under cool temperatures. The maximum reaches a pleasant 16°C (61°F), with an average of 7°C (44°F), while the nights can dip to a brisk -4°C (25°F). This month sees 11 days of rainfall, totaling around 98 mm (3.8 in), creating a cozy, atmospheric backdrop perfect for exploring the city’s historic sites. With an humidity level of 83%, be prepared for a refreshing ambiance as you wander through the picturesque streets, soaking in the festive spirit of this enchanting Italian destination.
In December, Siena, Italy, experiences a noticeable chill as winter sets in, with temperatures ranging from a minimum of -4°C (25°F) to a maximum of 16°C (61°F). The average temperature hovers around 7°C (44°F), indicating a brisk but not extreme cold. Compared to the preceding months, December marks a significant drop, following the milder climates of November, which saw warmer averages at around 11°C (51°F). This trend showcases the transition into the winter season, where the crisp air invites cozy gatherings and the charm of Siena's historical sites takes on a magical quality amidst the season's quiet beauty.
In December, Siena experiences a notable spike in precipitation, receiving an average of 98 mm (3.8 in) over approximately 11 days, marking a significant increase after the drier summer months. This surge is part of a trend that sees rainfall gradually intensifying as the year nears its close, particularly highlighted in November with 148 mm (5.8 in) across 15 days. The combination of cooler temperatures and increased precipitation prepares the picturesque city for winter, transforming the Tuscan landscape into a lush, vibrant scene. As residents and visitors alike brace for the damp weather, they can appreciate the beauty that rain brings to Siena’s historic charm, making each downpour a reminder of the region's dynamic climate.
In Siena, Italy, December brings a slight increase in humidity, averaging around 83%, suggesting a return to more moisture-laden air as the year draws to a close. This month sits just below the wettest periods of January and November, which both hover around 84%. From the peak humidity in early winter, there's a notable downward trend toward the summer months, where July and August see the driest conditions, with levels dipping to 57% and 55%, respectively. As the seasons shift, Siena experiences a gradual ebb and flow of humidity, culminating in the refreshing yet cooler atmosphere of December and hinting at the wetter months ahead.
In December, Siena experiences a low UV Index of 2, marking a shift towards minimal sun exposure risk compared to the preceding months. This moderation is reflected in a longer burn time of 45 minutes, allowing residents and visitors to enjoy the festive atmosphere with less concern for sun damage. As the year progresses, we observe a trend of gradually increasing UV levels from low in winter to very high in the summer months, especially in June and July where the UV Index peaked at 10. The contrast between the cozy winter days and the intense summer sun highlights the importance of adjusting sun protection strategies throughout the year. For detailed UV Index information, check out Siena UV Index.
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In Siena, December brings a serene transition into winter with 216 hours of sunshine, offering a gentle respite as the year draws to a close. While this is one of the lower totals of the year, it reflects a gradual decline in daylight from the sunniest months, July and June, which bask in over 400 hours. The month starts with a crisp, bright charm, mirroring the post-holiday calm that envelops the city, a precursor to the festive celebrations of the new year. As the days grow shorter, a tranquil ambiance sets in, inviting visitors to savor the rich history and architecture under the soft Tuscan sun, even as it dims.
As the year draws to a close, December in Siena, Italy, offers a modest 37% chance of sunny weather, making it one of the cooler months, though not the least hopeful for sunshine. While November sees an even lower likelihood at 32%, the sun's presence is not entirely absent, hinting at a slight uptick as the festive season unfolds. This month contrasts sharply with the vibrant summer months, where the sun reigns supreme with probabilities exceeding 60%. The overall trend suggests a gradual decline in sunny days from the peak of summer, yet December still holds the promise of occasional clear skies amid the crisp winter air, perfect for enjoying the enchanting medieval charm of Siena.
In Siena, Italy, December casts a soft glow with approximately 9 hours of daylight, mirroring the shorter days of January and November. As the year progresses from winter to summer, daylight duration gradually increases, peaking in June with a generous 15 hours. The sunlit hours begin to wane again come August, creating a rhythmic cycle that reflects the seasons. Each month transitions seamlessly into the next, with daylight fluctuating from 10 hours in February to the bright 14 hours of May, before dipping back down as winter approaches once more. This natural ebb and flow of light not only shapes the daily lives of Sienese residents but also enhances the enchanting atmosphere of this historic city throughout the year.
As December settles in Siena, the average wind speed gently decreases to 2.2 m/s (5 mph), providing a serene backdrop to the city's medieval charm. This marks a subtle shift from the brisker breezes felt in the earlier winter months, where speeds hovered around 2.5 m/s (6 mph) in November and spiked occasionally in October. Transitioning from the peak winds of fall, December's soft winds mingle with the festive atmosphere, inviting locals and visitors alike to explore cobblestone streets adorned with holiday lights. Throughout the year, Siena experiences a generally mild wind pattern, with the summer months often bringing the calmest conditions. Overall, December’s gentle winds complement the picturesque winter setting, making it an ideal time to embrace the beauty of this enchanting Italian city.
The weather in Siena changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of December's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Siena and find detailed weather information for every month.
In December, temperatures typically range from a minimum of -4°C (25°F) to a maximum of 16°C (61°F), averaging at 7°C (44°F). This month experiences relatively high precipitation, totaling around 98 mm (3.8 in) over about 11 days and maintaining a humidity of 83%. In contrast, January brings slightly colder conditions, with minimum temperatures dropping to -5°C (23°F) and an average of 5°C (41°F). The maximum temperatures in January are a bit lower as well, reaching up to 15°C (59°F). Precipitation is significantly reduced to 44 mm (1.7 in) over just 7 days, and the humidity remains similar at 84%. For more specific insights, you can check out Siena weather in January.
In December, the weather is characterized by cooler conditions, with temperatures ranging from a minimum of -4°C (25°F) to a maximum of 16°C (61°F) and an average of 7°C (44°F). The month sees a fair amount of precipitation, with 98 mm (3.8 in) falling over 11 days, and humidity levels are relatively high at 83%. Conversely, February experiences slightly colder mornings with a minimum temperature of -5°C (23°F), but it can warm up to a maximum of 20°C (68°F), averaging 7°C (46°F). Precipitation is less prevalent in February, totaling 68 mm (2.7 in) over just 8 days, and humidity drops to 76%. For more detailed weather insights, check out Siena weather in February.
The weather in December features a milder temperature range, with averages between -4°C (25°F) and 16°C (61°F), while March experiences slightly more frigid mornings, with a minimum temperature of -11°C (12°F) but peaks at a warmer 23°C (73°F). December has a higher overall precipitation of 98 mm (3.8 in) over 11 days and a humidity level of 83%, making it feel quite damp. In contrast, March sees less rainfall at 61 mm (2.4 in) over 8 days, contributing to a drier feel with lower humidity at 68%. For more details about the weather in March, you can visit Siena weather in March.
December and April in Siena present quite contrasting weather patterns. In December, temperatures range from a chilly -4°C (25°F) at night to a mild 16°C (61°F) during the day, averaging around 7°C (44°F). The month experiences significant precipitation, totaling 98 mm (3.8 in) over 11 days, contributing to a high humidity level of 83%. In contrast, April offers a much warmer climate, with temperatures varying from -3°C (27°F) to a pleasant maximum of 26°C (79°F), averaging 12°C (55°F). Moreover, rainfall is less frequent, totaling 81 mm (3.2 in) across 10 days, and the humidity level drops to 70%. For a closer look at what to expect, check out Siena weather in April.
December and May present distinctly different weather patterns. In December, temperatures range from a chilly minimum of -4°C (25°F) to a mild maximum of 16°C (61°F), with an average of 7°C (44°F). This month is characterized by high humidity at 83% and considerable precipitation of 98 mm (3.8 in) over about 11 days. Conversely, May enjoys much warmer temperatures, with a minimum of 3°C (37°F) and a maximum of 31°C (89°F), averaging around 16°C (62°F). The precipitation is slightly lower at 91 mm (3.6 in) but spans 13 days, with the humidity dropping to a more comfortable 69%. For a closer look at May's pleasant weather, you can check Siena weather in May.
In December, temperatures can drop as low as -4°C (25°F), with an average of 7°C (44°F) and highs reaching 16°C (61°F), creating a chilly atmosphere. The month experiences significant precipitation, averaging 98 mm (3.8 in) over 11 days, accompanied by high humidity at 83%. In contrast, June boasts a much milder climate, with temperatures starting at a minimum of 9°C (49°F) and soaring to an average of 22°C (71°F), peaking at a toasty 36°C (96°F). Rainfall is considerably less frequent, totaling 38 mm (1.5 in) over just 6 days, and humidity levels drop to a comfortable 62%. For more details on the pleasant weather in June, check out Siena weather in June.
December weather is characterized by much cooler temperatures, with a minimum of -4°C (25°F) and an average of 7°C (44°F), compared to the warm July averages of 13°C (56°F) at night and a peak of 36°C (97°F) during the day. Additionally, December experiences higher precipitation with 98 mm (3.8 in) over 11 days, while July is relatively dry, receiving just 38 mm (1.5 in) in about 6 days. The humidity is also notably higher in December at 83%, making the cold feel even more penetrating than the summer's milder 57% humidity in July. For a detailed look at what to expect, check out Siena weather in July.
December and August present a striking contrast in weather patterns. December typically sees much colder temperatures, with a minimum of -4°C (25°F) and an average of 7°C (44°F), while August enjoys a much warmer climate, featuring a minimum of 12°C (53°F) and an average of 25°C (77°F). Precipitation is notably higher in December, with 98 mm (3.8 in) falling over 11 days, in stark contrast to August's 34 mm (1.3 in) over just 5 days. Additionally, the humidity levels are higher in December at 83%, compared to 55% in August. For more detailed insights, you can check Siena weather in August.
In December, temperatures are significantly cooler, with lows averaging around -4°C (25°F) and highs reaching up to 16°C (61°F), while September experiences a much warmer climate with minimums of 7°C (45°F) and maximums soaring to 32°C (90°F). Precipitation levels are relatively close, with December receiving about 98 mm (3.8 in) over 11 days, compared to September's 84 mm (3.3 in) over 9 days. Additionally, December's humidity is notably higher at 83%, creating a chillier atmosphere than September's more comfortable 66%. For a detailed look at September weather in Siena, check out Siena weather in September.
December weather presents a notable contrast to October, with colder temperatures and increased precipitation. While October enjoys milder conditions with an average temperature of 15°C (59°F) and maximum highs reaching 27°C (81°F), December's average drops to around 7°C (44°F), peaking at a maximum of only 16°C (61°F). The total precipitation in December is slightly higher at 98 mm (3.8 in) over 11 days, compared to October's 91 mm (3.6 in) across 8 days. Additionally, December's humidity level is elevated at 83%, whereas October maintains a lower humidity of 79%. For more specific details, you can check Siena weather in October.
In comparing the weather of December to November, December experiences slightly colder temperatures, with a minimum of -4°C (25°F) compared to November's minimum of -3°C (27°F). The average temperature in December drops to 7°C (44°F), while November holds a warmer average of 11°C (51°F). Maximum temperatures also see a decline, reaching 16°C (61°F) in December versus 19°C (66°F) in November.
Precipitation levels are notably different, with December receiving 98 mm (3.8 in) of rain over 11 days, which is less than November's 148 mm (5.8 in) over 15 days. Humidity remains relatively stable, with December sitting at 83% and November at 84%. For more detailed information about weather conditions during November, you can visit Siena weather in November.
As December unfolds in Siena, the weather takes on a distinct character compared to the milder autumn months. While temperatures dip to a chilly average of 7°C and can even plummet to minimums around -4°C, the festive atmosphere is complemented by brisk air and occasional rainfall, as the city experiences 98 mm of precipitation over about 11 days. This month also brings a touch of humidity, averaging around 83%, creating a cozy but damp feel in the air. If you're curious about how Siena's climate evolves throughout the year, don't miss the detailed insights available at Siena Climate.