December Weather in Westfield, United States

Last updated: June 24, 2025

In Westfield, United States, the average temperature in December hovers around -1°C (31°F), with extremes ranging from a chilly -21°C (-6°F) to a mild 16°C (61°F). Expect 80 mm (3.2 in) of precipitation across about 12 days, and prepare for a moist atmosphere with an average humidity of 88%.

December Temperature in Westfield

In December in Westfield, the average temperature is -1°C (31°F). Maximum temperatures can reach 16°C (61°F), while minimums can drop as low as -21°C (-6°F). Travelers should be prepared for a wide range of temperatures during this month, ensuring they pack accordingly for both chilly and milder days.

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

The chart illustrates December temperature patterns in Westfield, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Westfield, December typically has an average temperature of -1°C (31°F), with highs reaching up to 16°C (61°F) and lows dropping to around -21°C (-6°F).
JanFebMarAprMayJunJulAugSepOctNovDec252834455765716962523731
Data source: Temperature data for Westfield 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 Westfield

In Westfield in December, the precipitation amount is 80 mm (3.2 in) over a span of 12 days.

December Precipitation Trends in Westfield

The chart displays monthly precipitation patterns in Westfield, 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 Westfield, December typically receives around 80 mm (3.2 inches) of precipitation spread over approximately 12 days.
JanFebMarAprMayJunJulAugSepOctNovDec6784751091169512479891197880
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Westfield

In Westfield in December, humidity is 88%. With an average temperature of -1°C (31°F), this humidity feels like a biting cold that penetrates your clothing, making outdoor exploration challenging and the air clingy, adding an extra chill that can make you feel even colder than the temperature suggests.

December Average Humidity in Westfield

This chart illustrates the average monthly humidity levels in Westfield, 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 Westfield is approximately 88%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec90%90%89%88%80%79%74%64%67%81%89%88%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Westfield

In Westfield 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 Westfield, you can visit Hourly UV Index in Westfield.

Maximum UV Index Levels in Westfield for December

The chart shows the monthly maximum UV Index (UVI) for Westfield 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 Westfield typically reaches 2, which falls under the low exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356910101098642
Data source: Westfield 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 Westfield Compares to Other Months

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

This table compares monthly weather conditions in Westfield, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-4°C (25°F)67 mm (2.6 inches)89%moderate
February Weather-2°C (28°F)84 mm (3.3 inches)90%moderate
March Weather1°C (35°F)75 mm (2.9 inches)89%high
April Weather7°C (46°F)109 mm (4.3 inches)88%very high
May Weather14°C (57°F)116 mm (4.6 inches)80%very high
June Weather19°C (66°F)95 mm (3.7 inches)79%very high
July Weather21°C (71°F)124 mm (4.9 inches)74%very high
August Weather20°C (69°F)79 mm (3.1 inches)64%very high
September Weather17°C (62°F)89 mm (3.5 inches)67%very high
October Weather11°C (52°F)119 mm (4.7 inches)81%high
November Weather3°C (38°F)78 mm (3.1 inches)89%moderate
December Weather-1°C (31°F)80 mm (3.2 inches)88%low

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