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December Weather in San Francisco, Peru

Last updated: August 27, 2025

In San Francisco, Peru, the average temperature in December is a pleasant 19°C (67°F). Expect a minimum of 16°C (60°F) and a comfortable maximum of 25°C (77°F). During this time, the region sees about 13 mm (0.5 in) of precipitation spread over 4 days, resulting in an average humidity of 87%. Plan your visit accordingly for an enjoyable experience!

December Temperature in San Francisco

In December, in San Francisco, the average temperature is 19°C (67°F). The maximum can reach 25°C (77°F), and the minimum can be as low as 16°C (60°F). This pleasant weather makes San Francisco an ideal destination for travelers looking to enjoy mild temperatures and outdoor activities.

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

The chart illustrates December temperature patterns in San Francisco, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Francisco, December typically has an average temperature of 19°C (67°F), with highs reaching up to 25°C (77°F) and lows dropping to around 16°C (60°F).
JanFebMarAprMayJunJulAugSepOctNovDec686969686664646464646567
Data source: Temperature data for San Francisco 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 San Francisco

In San Francisco in December, the precipitation amount is 13 mm (0.5 in) over a span of 4 days.

December Precipitation Trends in San Francisco

The chart displays monthly precipitation patterns in San Francisco, 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 Francisco, December typically receives around 13 mm (0.5 inches) of precipitation spread over approximately 4 days.
JanFebMarAprMayJunJulAugSepOctNovDec73845820421125513
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in San Francisco

In San Francisco in December, humidity is 87%. With an average temperature of 19°C (67°F), this humidity feels like a warm blanket wrapping around you, making traveling a bit heavier and leaving you craving for refreshing drinks and shade throughout the day.

December Average Humidity in San Francisco

This chart illustrates the average monthly humidity levels in San Francisco, 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 Francisco is approximately 87%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec89%89%90%89%83%69%56%51%53%68%82%87%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in San Francisco

In San Francisco in December, the maximum UV index reaches an alarming 15, which falls into the extreme Exposure Category. With a time to burn of just 10 minutes, it's crucial to take precautions. For detailed information, you can check the Hourly UV Index in San Francisco.

Maximum UV Index Levels in San Francisco for December

The chart shows the monthly maximum UV Index (UVI) for San Francisco 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 Francisco typically reaches 15, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec151615141110111214151615
Data source: San Francisco 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 Francisco Compares to Other Months

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

This table compares monthly weather conditions in San Francisco, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather20°C (69°F)73 mm (2.9 inches)89%extreme
February Weather21°C (69°F)84 mm (3.3 inches)89%extreme
March Weather21°C (70°F)58 mm (2.3 inches)90%extreme
April Weather20°C (68°F)20 mm (0.8 inches)89%extreme
May Weather19°C (66°F)4 mm (0.2 inches)83%extreme
June Weather18°C (65°F)1 mm (0.1 inches)69%very high
July Weather18°C (64°F)1 mm (0.0 inches)56%extreme
August Weather18°C (64°F)0 mm (0.0 inches)50%extreme
September Weather18°C (64°F)2 mm (0.1 inches)53%extreme
October Weather18°C (65°F)5 mm (0.2 inches)68%extreme
November Weather19°C (66°F)5 mm (0.2 inches)81%extreme
December Weather19°C (67°F)13 mm (0.5 inches)87%extreme

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