nomadseason

December Weather in Somerville, United States

Last updated: June 24, 2025

In Somerville, United States, the average temperature in December is a cool 8°C (47°F), with fluctuations between a chilling -10°C (15°F) and a pleasant 24°C (76°F). This month sees 145 mm (5.7 in) of precipitation spread over 11 days, contributing to an average humidity of 88%. Don't forget your umbrella and warm layers!

December Temperature in Somerville

In December in Somerville, the average temperature is 8°C (47°F), with a maximum that can reach 24°C (76°F) and a minimum that can drop as low as -10°C (15°F). It's advisable to pack for a range of weather conditions to fully enjoy your travels during this time.

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 8°C (47°F), with highs reaching up to 24°C (76°F) and lows dropping to around -10°C (15°F).
JanFebMarAprMayJunJulAugSepOctNovDec424655617178817975645047
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 precipitation amount is 145 mm (5.7 in) over a span 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 145 mm (5.7 inches) of precipitation spread over approximately 11 days.
JanFebMarAprMayJunJulAugSepOctNovDec10017216513510510912511411510575145
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 88%. With an average temperature of 8°C (47°F), this humidity feels like a thick, damp blanket wrapping around you, making even short walks feel heavy and uninviting for travel.

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 88%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec86%85%84%81%83%83%80%74%70%73%85%88%
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 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Somerville, you can check the information here.

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 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec46810111111109753
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 Weather6°C (42°F)100 mm (4.0 inches)86%moderate
February Weather8°C (46°F)172 mm (6.8 inches)85%high
March Weather13°C (55°F)165 mm (6.5 inches)84%very high
April Weather16°C (61°F)135 mm (5.3 inches)81%very high
May Weather22°C (72°F)105 mm (4.1 inches)83%extreme
June Weather26°C (78°F)109 mm (4.3 inches)83%extreme
July Weather27°C (81°F)124 mm (4.9 inches)80%extreme
August Weather26°C (79°F)114 mm (4.5 inches)73%very high
September Weather24°C (76°F)114 mm (4.5 inches)70%very high
October Weather18°C (65°F)105 mm (4.1 inches)73%high
November Weather10°C (51°F)75 mm (2.9 inches)85%moderate
December Weather8°C (47°F)145 mm (5.7 inches)88%moderate

Compare Somerville's Climate with Cities Worldwide