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December Weather in Head of the Harbor, United States

Last updated: June 24, 2025

In December, the average temperature in Head of the Harbor, United States hovers around 4°C (39°F), with a minimum plunging to -11°C (13°F) and a maximum peaking at 17°C (63°F). Expect about 119 mm (4.7 in) of precipitation over 11 days, and prepare for an average humidity level of 80%, making this month both chilly and damp.

December Temperature in Head of the Harbor

In December in Head of the Harbor, the average temperature is 4°C (39°F). Maximums can reach 17°C (63°F), while minimums can drop as low as -11°C (13°F). Travelers should be prepared for a wide range of temperatures and pack accordingly for both milder and colder conditions.

December Weather in Head of the Harbor: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Head of the Harbor, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Head of the Harbor, December typically has an average temperature of 4°C (39°F), with highs reaching up to 17°C (63°F) and lows dropping to around -11°C (13°F).
JanFebMarAprMayJunJulAugSepOctNovDec343641505970777569604739
Data source: Temperature data for Head of the Harbor 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 Head of the Harbor

In Head of the Harbor in December, the total precipitation amount is 119 mm (4.7 in), which occurs over the course of 11 days.

December Precipitation Trends in Head of the Harbor

The chart displays monthly precipitation patterns in Head of the Harbor, 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 Head of the Harbor, December typically receives around 119 mm (4.7 inches) of precipitation spread over approximately 11 days.
JanFebMarAprMayJunJulAugSepOctNovDec709995119110901321089212994119
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Head of the Harbor

In Head of the Harbor in December, humidity is 80%. With an average temperature of 4°C (39°F), this humidity feels like a damp chill that seeps into your bones, making travel uncomfortable and requiring extra layers to stay warm while navigating through the misty streets.

December Average Humidity in Head of the Harbor

This chart illustrates the average monthly humidity levels in Head of the Harbor, 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 Head of the Harbor is approximately 80%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec84%82%81%78%70%69%62%65%68%74%82%80%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Head of the Harbor

In Head of the Harbor 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 Head of the Harbor, you can visit Hourly UV Index in Head of the Harbor.

Maximum UV Index Levels in Head of the Harbor for December

The chart shows the monthly maximum UV Index (UVI) for Head of the Harbor 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 Head of the Harbor typically reaches 2, which falls under the low exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec35681010998642
Data source: Head of the Harbor 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 Head of the Harbor Compares to Other Months

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

This table compares monthly weather conditions in Head of the Harbor, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather1°C (34°F)70 mm (2.8 inches)84%moderate
February Weather2°C (36°F)99 mm (3.9 inches)82%moderate
March Weather5°C (41°F)95 mm (3.8 inches)81%high
April Weather10°C (50°F)118 mm (4.7 inches)78%very high
May Weather15°C (60°F)110 mm (4.3 inches)69%very high
June Weather21°C (70°F)90 mm (3.5 inches)69%very high
July Weather25°C (77°F)132 mm (5.2 inches)62%very high
August Weather24°C (75°F)108 mm (4.3 inches)65%very high
September Weather21°C (69°F)92 mm (3.6 inches)68%very high
October Weather15°C (60°F)129 mm (5.1 inches)74%high
November Weather8°C (47°F)94 mm (3.7 inches)82%moderate
December Weather4°C (39°F)119 mm (4.7 inches)80%low

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