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December Weather in South Boston, United States

Last updated: June 24, 2025

In December, the average temperature in South Boston, United States is a cool 7°C (45°F). Expect temperatures to dip as low as -9°C (16°F) and rise to a maximum of 23°C (73°F). With an average humidity of 85%, prepare for a damp atmosphere, as 96 mm (3.8 in) of precipitation typically graces the area over 9 days.

December Temperature in South Boston

In December in South Boston, the average temperature is 7°C (45°F), with maximums reaching 23°C (73°F) and minimums dropping as low as -9°C (16°F). Be prepared for a wide range of temperatures when traveling to South Boston during this month.

December Weather in South Boston: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in South Boston, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In South Boston, December typically has an average temperature of 7°C (45°F), with highs reaching up to 23°C (73°F) and lows dropping to around -9°C (16°F).
JanFebMarAprMayJunJulAugSepOctNovDec414651606976817873644945
Data source: Temperature data for South Boston generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in South Boston

In South Boston in December, the total precipitation amount is 96 mm (3.8 in) spread over a period of 9 days.

December Precipitation Trends in South Boston

The chart displays monthly precipitation patterns in South Boston, 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 South Boston, December typically receives around 96 mm (3.8 inches) of precipitation spread over approximately 9 days.
JanFebMarAprMayJunJulAugSepOctNovDec73108721201119269109981067596
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in South Boston

In South Boston in December, humidity is 85%. With an average temperature of 7°C (45°F), this humidity feels like a damp chill that clings to your skin, making outdoor activities less enjoyable and requiring extra layers to stay comfortable while traveling.

December Average Humidity in South Boston

This chart illustrates the average monthly humidity levels in South Boston, 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 South Boston is approximately 85%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec84%84%84%82%83%83%79%77%75%81%87%85%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in South Boston

In South Boston 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 South Boston, you can check the information here.

Maximum UV Index Levels in South Boston for December

The chart shows the monthly maximum UV Index (UVI) for South Boston 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 South Boston typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3679111110109853
Data source: South Boston 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 South Boston Compares to Other Months

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

This table compares monthly weather conditions in South Boston, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather5°C (41°F)73 mm (2.9 inches)84%moderate
February Weather8°C (46°F)108 mm (4.2 inches)84%high
March Weather11°C (51°F)72 mm (2.8 inches)84%high
April Weather16°C (61°F)120 mm (4.7 inches)82%very high
May Weather21°C (69°F)110 mm (4.3 inches)82%extreme
June Weather24°C (76°F)92 mm (3.6 inches)83%extreme
July Weather27°C (81°F)69 mm (2.7 inches)79%very high
August Weather26°C (79°F)109 mm (4.3 inches)77%very high
September Weather23°C (74°F)98 mm (3.9 inches)75%very high
October Weather18°C (64°F)106 mm (4.2 inches)81%very high
November Weather10°C (50°F)75 mm (3.0 inches)87%moderate
December Weather7°C (45°F)96 mm (3.8 inches)85%moderate

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