December Weather in Penn Valley, United States

Last updated: June 24, 2025

In December, the average temperature in Penn Valley, United States hovers around 8°C (47°F). During this time, temperatures can range from a chilly -2°C (29°F) to a warm 23°C (74°F). Precipitation is noteworthy, with around 170 mm (6.7 in) expected over 11 days, and the atmosphere remains quite humid, with average humidity levels at 83%.

December Temperature in Penn Valley

In December in Penn Valley, the average temperature is 8°C (47°F), with maximums reaching up to 23°C (74°F) and minimums dropping as low as -2°C (29°F). Travelers should be prepared for a wide range of temperatures during this time.

December Weather in Penn Valley: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Penn Valley, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Penn Valley, December typically has an average temperature of 8°C (47°F), with highs reaching up to 23°C (74°F) and lows dropping to around -2°C (29°F).

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

December Precipitation in Penn Valley

In Penn Valley in December, the precipitation amount is 170 mm (6.7 in) over the course of 11 days.

December Precipitation Trends in Penn Valley

The chart displays monthly precipitation patterns in Penn Valley, 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 Penn Valley, December typically receives around 170 mm (6.7 inches) of precipitation spread over approximately 11 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 Penn Valley

In Penn Valley in December humidity is 83%. With an average temperature of 8°C (47°F), this humidity feels like a chilly dampness that clings to your skin, making travel uncomfortable and leaving you yearning for warmth and dryness as you explore.

December Average Humidity in Penn Valley

This chart illustrates the average monthly humidity levels in Penn Valley, 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 Penn Valley is approximately 83%, 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 Penn Valley

In Penn Valley 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 Penn Valley, you can check the information here.

Maximum UV Index Levels in Penn Valley for December

The chart shows the monthly maximum UV Index (UVI) for Penn Valley 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 Penn Valley typically reaches 3, which falls under the moderate exposure category.

Data source: Penn Valley 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 Penn Valley Compares to Other Months

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

This table compares monthly weather conditions in Penn Valley, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	9°C (48°F)	196 mm (7.7 inches)	84%	moderate
February Weather	9°C (49°F)	202 mm (8.0 inches)	84%	moderate
March Weather	11°C (52°F)	191 mm (7.5 inches)	83%	high
April Weather	15°C (59°F)	89 mm (3.5 inches)	81%	very high
May Weather	19°C (66°F)	48 mm (1.9 inches)	74%	very high
June Weather	24°C (76°F)	9 mm (0.3 inches)	64%	extreme
July Weather	27°C (81°F)	1 mm (0.0 inches)	44%	extreme
August Weather	26°C (79°F)	1 mm (0.0 inches)	36%	very high
September Weather	23°C (73°F)	12 mm (0.5 inches)	44%	very high
October Weather	17°C (63°F)	62 mm (2.4 inches)	65%	high
November Weather	12°C (53°F)	115 mm (4.5 inches)	84%	moderate
December Weather	8°C (47°F)	170 mm (6.7 inches)	83%	moderate