December Weather in Atascadero, United States

Last updated: June 24, 2025

In December, the average temperature in Atascadero, United States is a cool 11°C (51°F), with minimums dipping to 1°C (33°F) and maximums reaching 25°C (77°F). Expect 62 mm (2.4 in) of precipitation over approximately 6 days, accompanied by an average humidity of 76%, making for a crisp yet refreshing atmosphere.

December Temperature in Atascadero

In December in Atascadero, the average temperature is 11°C (51°F), with maximums reaching 25°C (77°F) and minimums dropping as low as 1°C (33°F). It's a great time for travelers to enjoy mild weather, so pack accordingly for both warm days and cooler evenings.

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

The chart illustrates December temperature patterns in Atascadero, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Atascadero, December typically has an average temperature of 11°C (51°F), with highs reaching up to 25°C (77°F) and lows dropping to around 1°C (33°F).

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

December Precipitation in Atascadero

In Atascadero in December, the precipitation amount is 62 mm (2.4 in), spread over the course of 6 days.

December Precipitation Trends in Atascadero

The chart displays monthly precipitation patterns in Atascadero, 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 Atascadero, December typically receives around 62 mm (2.4 inches) of precipitation spread over approximately 6 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 Atascadero

In Atascadero in December, humidity is 76%. With an average temperature of 11°C (51°F), this humidity feels like a damp chill that settles into your bones, making outdoor activities uncomfortable and potentially discouraging for traveling.

December Average Humidity in Atascadero

This chart illustrates the average monthly humidity levels in Atascadero, 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 Atascadero is approximately 76%, 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 Atascadero

In Atascadero 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 Atascadero, you can check the information here.

Maximum UV Index Levels in Atascadero for December

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

Data source: Atascadero 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 Atascadero Compares to Other Months

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

This table compares monthly weather conditions in Atascadero, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	11°C (51°F)	94 mm (3.7 inches)	80%	moderate
February Weather	11°C (52°F)	68 mm (2.7 inches)	83%	moderate
March Weather	12°C (54°F)	75 mm (3.0 inches)	80%	very high
April Weather	14°C (58°F)	20 mm (0.8 inches)	76%	very high
May Weather	16°C (61°F)	10 mm (0.4 inches)	75%	extreme
June Weather	19°C (66°F)	1 mm (0.0 inches)	74%	extreme
July Weather	20°C (68°F)	1 mm (0.0 inches)	75%	extreme
August Weather	20°C (69°F)	1 mm (0.0 inches)	72%	extreme
September Weather	20°C (68°F)	1 mm (0.0 inches)	70%	very high
October Weather	17°C (63°F)	9 mm (0.3 inches)	70%	high
November Weather	14°C (57°F)	29 mm (1.1 inches)	74%	moderate
December Weather	11°C (51°F)	62 mm (2.4 inches)	76%	moderate