December Weather in Fairfield, United States

Last updated: June 24, 2025

In December, the average temperature in Fairfield, United States hovers around 0°C (33°F). Expect temperatures to vary widely, with minimums plummeting to -22°C (-7°F) and highs reaching a pleasant 23°C (74°F). During this month, anticipate about 43 mm (1.7 in) of precipitation over approximately 5 days, coupled with an average humidity of 84%, creating a uniquely crisp atmosphere.

December Temperature in Fairfield

In December in Fairfield, the average temperature is 0°C (33°F), with maximums reaching 23°C (74°F) and minimums dropping as low as -22°C (-7°F). This range makes it essential to pack layers and be prepared for both mild and frigid conditions while traveling.

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 0°C (33°F), with highs reaching up to 23°C (74°F) and lows dropping to around -22°C (-7°F).

Data source: Temperature data for Fairfield generated using information from the Copernicus Climate Change Service.

December Precipitation in Fairfield

In Fairfield in December, the precipitation amount is 43 mm (1.7 in) over the course of 5 days.

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 43 mm (1.7 inches) of precipitation spread over approximately 5 days.

Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

December Humidity in Fairfield

In Fairfield in December humidity is 84%. With average temperature 0°C (33°F), this humidity feels like a damp chill that seeps into your bones, making outdoor adventures less enjoyable and travel plans challenging.

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.

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.

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.
	Temperature	Precipitation	Humidity	UV
January Weather	-4°C (25°F)	52 mm (2.0 inches)	81%	moderate
February Weather	-3°C (27°F)	55 mm (2.2 inches)	81%	moderate
March Weather	5°C (42°F)	91 mm (3.6 inches)	81%	high
April Weather	10°C (51°F)	83 mm (3.3 inches)	82%	very high
May Weather	18°C (64°F)	160 mm (6.3 inches)	78%	very high
June Weather	24°C (75°F)	133 mm (5.2 inches)	81%	extreme
July Weather	25°C (78°F)	70 mm (2.8 inches)	79%	very high
August Weather	24°C (75°F)	73 mm (2.9 inches)	77%	very high
September Weather	21°C (69°F)	121 mm (4.8 inches)	78%	very high
October Weather	12°C (54°F)	124 mm (4.9 inches)	78%	high
November Weather	4°C (40°F)	52 mm (2.0 inches)	87%	moderate
December Weather	0°C (33°F)	43 mm (1.7 inches)	84%	moderate