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December Weather in Fairfield, United States

Last updated: June 24, 2025

In December, the average temperature in Fairfield, United States hovers around 3°C (38°F). However, temperatures can vary significantly, with minimums plummeting to -13°C (10°F) and maximums reaching a mild 18°C (64°F). The region experiences an average humidity of 84% and sees about 92 mm (3.6 in) of precipitation spread over 9 days. Prepare for a mix of chilly days and occasional wet weather!

December Temperature in Fairfield

In December in Fairfield, the average temperature is 3°C (38°F), with maximums reaching 18°C (64°F) and minimums dropping as low as -13°C (10°F). Be prepared for a wide range of temperatures during your travels!

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

The chart illustrates December temperature patterns in Fairfield, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Fairfield, December typically has an average temperature of 3°C (38°F), with highs reaching up to 18°C (64°F) and lows dropping to around -13°C (10°F).
JanFebMarAprMayJunJulAugSepOctNovDec343743546472787569594438
Data source: Temperature data for Fairfield 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 Fairfield

In Fairfield in December, the precipitation amount is 92 mm (3.6 in) during 9 days, indicating a relatively wet period for the region.

December Precipitation Trends in Fairfield

The chart displays monthly precipitation patterns in Fairfield, 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 Fairfield, December typically receives around 92 mm (3.6 inches) of precipitation spread over approximately 9 days.
JanFebMarAprMayJunJulAugSepOctNovDec629794981331031341191181008692
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Fairfield

In Fairfield in December, humidity is 84%. With an average temperature of 3°C (38°F), this humidity feels like a damp chill that seeps into your bones, making traveling uncomfortable as the cold air clings to you and the moisture creates an oppressive heaviness in the atmosphere.

December Average Humidity in Fairfield

This chart illustrates the average monthly humidity levels in Fairfield, 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 Fairfield is approximately 84%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec84%83%83%81%78%79%74%72%75%81%85%84%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Fairfield

In Fairfield 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 Fairfield, you can check the information here.

Maximum UV Index Levels in Fairfield for December

The chart shows the monthly maximum UV Index (UVI) for Fairfield 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 Fairfield typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec357910101098743
Data source: Fairfield 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 Fairfield Compares to Other Months

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

This table compares monthly weather conditions in Fairfield, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather1°C (34°F)62 mm (2.4 inches)84%moderate
February Weather3°C (38°F)97 mm (3.8 inches)83%moderate
March Weather6°C (44°F)94 mm (3.7 inches)83%high
April Weather12°C (54°F)98 mm (3.9 inches)81%very high
May Weather18°C (64°F)132 mm (5.2 inches)78%very high
June Weather22°C (73°F)103 mm (4.1 inches)79%very high
July Weather25°C (78°F)134 mm (5.3 inches)74%very high
August Weather24°C (76°F)118 mm (4.7 inches)72%very high
September Weather21°C (70°F)118 mm (4.6 inches)75%very high
October Weather15°C (60°F)100 mm (3.9 inches)81%high
November Weather7°C (45°F)86 mm (3.4 inches)85%moderate
December Weather3°C (38°F)92 mm (3.6 inches)84%moderate

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