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December Weather in Ashburn, United States

Last updated: June 24, 2025

In Ashburn, United States, the average temperature in December hovers around 12°C (54°F). Expect a chilly minimum of -4°C (24°F), while temperatures can reach a pleasant maximum of 27°C (80°F). During this month, anticipate 119 mm (4.7 in) of precipitation spread over about 10 days, and prepare for high humidity levels at an average of 88%.

December Temperature in Ashburn

In December in Ashburn, the average temperature is 12°C (54°F). The maximum can reach 27°C (80°F) and the minimum can be as low as -4°C (24°F). This variety in temperatures makes it essential for travelers to pack layers to enjoy their stay comfortably.

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

The chart illustrates December temperature patterns in Ashburn, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Ashburn, December typically has an average temperature of 12°C (54°F), with highs reaching up to 27°C (80°F) and lows dropping to around -4°C (24°F).
JanFebMarAprMayJunJulAugSepOctNovDec525762677580838280725854
Data source: Temperature data for Ashburn 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 Ashburn

In Ashburn in December, the total precipitation amount is 119 mm (4.7 in) over the span of 10 days.

December Precipitation Trends in Ashburn

The chart displays monthly precipitation patterns in Ashburn, 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 Ashburn, December typically receives around 119 mm (4.7 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec791158610481951141081159056119
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Ashburn

In Ashburn in December, humidity is 88%. With an average temperature of 12°C (54°F), this humidity feels like a thick, damp blanket, making traveling a bit uncomfortable as the air clings to your skin, causing you to sweat even in cooler weather.

December Average Humidity in Ashburn

This chart illustrates the average monthly humidity levels in Ashburn, 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 Ashburn is approximately 88%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%82%80%76%73%74%80%79%83%77%84%88%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Ashburn

In Ashburn in December, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Ashburn for better planning.

Maximum UV Index Levels in Ashburn for December

The chart shows the monthly maximum UV Index (UVI) for Ashburn 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 Ashburn typically reaches 4, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec589101111111110864
Data source: Ashburn 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 Ashburn Compares to Other Months

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

This table compares monthly weather conditions in Ashburn, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather11°C (52°F)79 mm (3.1 inches)85%moderate
February Weather14°C (58°F)115 mm (4.5 inches)82%very high
March Weather17°C (62°F)86 mm (3.4 inches)80%very high
April Weather19°C (67°F)104 mm (4.1 inches)76%very high
May Weather24°C (76°F)81 mm (3.2 inches)73%extreme
June Weather27°C (81°F)95 mm (3.8 inches)74%extreme
July Weather28°C (83°F)114 mm (4.5 inches)80%extreme
August Weather28°C (83°F)108 mm (4.2 inches)79%extreme
September Weather26°C (80°F)114 mm (4.5 inches)83%very high
October Weather22°C (72°F)90 mm (3.5 inches)77%very high
November Weather15°C (58°F)56 mm (2.2 inches)84%high
December Weather12°C (54°F)119 mm (4.7 inches)88%moderate

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