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December Weather in Mount Washington, United States

Last updated: June 24, 2025

In December, the average temperature in Mount Washington, United States typically hovers around 5°C (42°F). However, be prepared for a range: temperatures can dip as low as -12°C (10°F) or soar up to 22°C (72°F). Expect about 115 mm (4.5 in) of precipitation spread over 10 days, contributing to an average humidity of a notable 88%.

December Temperature in Mount Washington

In December in Mount Washington, the average temperature is 5°C (42°F). Maximum temperatures can reach 22°C (72°F), while minimums can drop as low as -12°C (10°F). Be prepared for a wide range of temperatures, making layering essential for your travels.

December Weather in Mount Washington: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Mount Washington, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Mount Washington, December typically has an average temperature of 5°C (42°F), with highs reaching up to 22°C (72°F) and lows dropping to around -12°C (10°F).
JanFebMarAprMayJunJulAugSepOctNovDec364048566874787672614541
Data source: Temperature data for Mount Washington 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 Mount Washington

In Mount Washington in December, the precipitation amount is 115 mm (4.5 in) over a span of 10 days.

December Precipitation Trends in Mount Washington

The chart displays monthly precipitation patterns in Mount Washington, 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 Mount Washington, December typically receives around 115 mm (4.5 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec931421371421211611019611910288115
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Mount Washington

In Mount Washington in December humidity is 88%. With an average temperature of 5°C (42°F), this humidity feels like a damp chill that seeps into your bones, making outdoor activities less appealing and leading you to seek warmth indoors instead.

December Average Humidity in Mount Washington

This chart illustrates the average monthly humidity levels in Mount Washington, 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 Mount Washington is approximately 88%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%86%86%82%83%83%80%74%71%78%88%88%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Mount Washington

In Mount Washington 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 Mount Washington, you can check the information here.

Maximum UV Index Levels in Mount Washington for December

The chart shows the monthly maximum UV Index (UVI) for Mount Washington 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 Mount Washington typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3579101110109753
Data source: Mount Washington 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 Mount Washington Compares to Other Months

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

This table compares monthly weather conditions in Mount Washington, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather2°C (36°F)93 mm (3.7 inches)87%moderate
February Weather5°C (41°F)142 mm (5.6 inches)86%moderate
March Weather9°C (48°F)137 mm (5.4 inches)86%high
April Weather13°C (56°F)142 mm (5.6 inches)82%very high
May Weather20°C (68°F)121 mm (4.7 inches)82%very high
June Weather24°C (75°F)161 mm (6.3 inches)83%extreme
July Weather26°C (79°F)101 mm (4.0 inches)80%very high
August Weather25°C (77°F)95 mm (3.8 inches)74%very high
September Weather22°C (72°F)119 mm (4.7 inches)71%very high
October Weather16°C (61°F)102 mm (4.0 inches)78%high
November Weather7°C (46°F)88 mm (3.5 inches)88%moderate
December Weather5°C (42°F)115 mm (4.5 inches)88%moderate

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