nomadseason

December Weather in Somerville, United States

Last updated: June 24, 2025

In Somerville, United States, the average temperature in December hovers around -2°C (28°F), with minimums dipping to -24°C (-11°F) and maximums reaching up to 15°C (60°F). Expect 121 mm (4.8 in) of precipitation over approximately 11 days, accompanied by a high average humidity of 84%. Stay prepared for a mix of chilly and damp weather!

December Temperature in Somerville

In December in Somerville, the average temperature is -2°C (28°F), with maximums reaching up to 15°C (60°F) and minimums plummeting as low as -24°C (-11°F). Travelers should be prepared for a wide range of temperatures, ensuring they pack appropriately for both chilly and moderately warm conditions.

December Weather in Somerville: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Somerville, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Somerville, December typically has an average temperature of -2°C (28°F), with highs reaching up to 15°C (60°F) and lows dropping to around -24°C (-11°F).
JanFebMarAprMayJunJulAugSepOctNovDec242632445465707062513828
Data source: Temperature data for Somerville generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in Somerville

In Somerville in December, the total precipitation amount is 121 mm (4.8 in), which occurs over the course of 11 days.

December Precipitation Trends in Somerville

The chart displays monthly precipitation patterns in Somerville, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In Somerville, December typically receives around 121 mm (4.8 inches) of precipitation spread over approximately 11 days.
JanFebMarAprMayJunJulAugSepOctNovDec88877212481641057773129109121
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

December Humidity in Somerville

In Somerville in December humidity is 84%. With an average temperature of -2°C (28°F), this humidity feels like a biting chill that cuts through layers of clothing, making outdoor activities uncomfortable and travel challenging.

December Average Humidity in Somerville

This chart illustrates the average monthly humidity levels in Somerville, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Somerville is approximately 84%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%88%85%81%76%74%74%74%77%82%85%84%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Somerville

In Somerville in December, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Somerville, you can visit Hourly UV Index in Somerville.

Maximum UV Index Levels in Somerville for December

The chart shows the monthly maximum UV Index (UVI) for Somerville in December, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In December, the maximum UV index in Somerville typically reaches 2, which falls under the low exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec2457910987532
Data source: Somerville December UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How December Weather in Somerville Compares to Other Months

Weather in Somerville varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Somerville, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Somerville, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-4°C (25°F)88 mm (3.5 inches)88%low
February Weather-3°C (26°F)86 mm (3.4 inches)88%moderate
March Weather0°C (33°F)72 mm (2.8 inches)85%moderate
April Weather7°C (44°F)124 mm (4.9 inches)81%high
May Weather12°C (55°F)80 mm (3.2 inches)76%very high
June Weather18°C (65°F)64 mm (2.5 inches)74%very high
July Weather21°C (71°F)105 mm (4.1 inches)74%very high
August Weather21°C (70°F)77 mm (3.0 inches)74%very high
September Weather17°C (63°F)73 mm (2.9 inches)77%high
October Weather11°C (52°F)129 mm (5.1 inches)82%moderate
November Weather3°C (38°F)109 mm (4.3 inches)85%moderate
December Weather-2°C (28°F)121 mm (4.8 inches)84%low

Compare Somerville's Climate with Cities Worldwide