December Weather in San Diego, Mexico

Last updated: August 27, 2025

In December, the average temperature in San Diego, Mexico hovers around 13°C (57°F), with a minimum dipping to 0°C (32°F) and a maximum reaching 25°C (77°F). Expect about 51 mm (2.0 in) of precipitation spread over 9 days, and a notably high average humidity of 91%, making it a unique and refreshing month to experience!

December Temperature in San Diego

In December in San Diego, the average temperature is 13°C (57°F). Maximums can reach 25°C (77°F) and minimums can be as low as 0°C (32°F). Be sure to pack layers to accommodate the varying temperatures throughout the day.

December Weather in San Diego: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in San Diego, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Diego, December typically has an average temperature of 13°C (57°F), with highs reaching up to 25°C (77°F) and lows dropping to around 0°C (32°F).

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

December Precipitation in San Diego

In San Diego in December, the total precipitation amount is 51 mm (2.0 in) spread over 9 days.

December Precipitation Trends in San Diego

The chart displays monthly precipitation patterns in San Diego, 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 San Diego, December typically receives around 51 mm (2.0 inches) of precipitation spread over approximately 9 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 San Diego

In San Diego in December, humidity is 91%. With an average temperature of 13°C (57°F), this humidity feels like an uncomfortable dampness that clings to your skin, making outdoor activities less enjoyable and leading to a constant feeling of being weighed down.

December Average Humidity in San Diego

This chart illustrates the average monthly humidity levels in San Diego, 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 San Diego is approximately 91%, 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 San Diego

In San Diego in December, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in San Diego.

Maximum UV Index Levels in San Diego for December

The chart shows the monthly maximum UV Index (UVI) for San Diego 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 San Diego typically reaches 8, which falls under the very high exposure category.

Data source: San Diego 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 San Diego Compares to Other Months

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

This table compares monthly weather conditions in San Diego, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	13°C (55°F)	88 mm (3.5 inches)	88%	very high
February Weather	15°C (58°F)	64 mm (2.5 inches)	86%	extreme
March Weather	16°C (61°F)	93 mm (3.7 inches)	84%	extreme
April Weather	18°C (65°F)	133 mm (5.2 inches)	81%	extreme
May Weather	19°C (67°F)	190 mm (7.5 inches)	82%	extreme
June Weather	19°C (66°F)	262 mm (10.3 inches)	81%	extreme
July Weather	18°C (65°F)	210 mm (8.3 inches)	81%	extreme
August Weather	18°C (65°F)	291 mm (11.4 inches)	82%	extreme
September Weather	18°C (65°F)	339 mm (13.3 inches)	86%	extreme
October Weather	17°C (63°F)	217 mm (8.5 inches)	90%	extreme
November Weather	15°C (59°F)	111 mm (4.4 inches)	91%	very high
December Weather	13°C (57°F)	51 mm (2.0 inches)	91%	very high