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December Weather in San Francisco, Peru

Last updated: August 27, 2025

In December, the average temperature in San Francisco, Peru is a comfortable 16°C (62°F), with minimums dipping to 11°C (52°F) and maximums reaching 26°C (78°F). Expect ample rain, with 325 mm (12.8 in) of precipitation spread over 26 days, contributing to a high average humidity of 89%. Whether you're planning outdoor activities or enjoying cozy indoor settings, be prepared for a mix of conditions!

December Temperature in San Francisco

In December in San Francisco, the average temperature is 16°C (62°F). The maximum can reach 26°C (78°F), while the minimum can drop as low as 11°C (52°F). This mild climate makes San Francisco a perfect destination for travelers seeking pleasant weather during their visit.

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 16°C (62°F), with highs reaching up to 26°C (78°F) and lows dropping to around 11°C (52°F).
JanFebMarAprMayJunJulAugSepOctNovDec616161605959585859616261
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 325 mm (12.8 in) spread across 26 days, highlighting the region's characteristic rainy season.

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 325 mm (12.8 inches) of precipitation spread over approximately 26 days.
JanFebMarAprMayJunJulAugSepOctNovDec408401465282105402764189299325325
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 89%. With an average temperature of 16°C (62°F), this humidity feels like a damp blanket enveloping you, making every step slightly sticky and the air thick, which can be uncomfortable for traveling.

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 89%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec93%92%92%90%85%70%55%44%52%65%81%89%
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 is 16, which corresponds to an extreme Exposure Category. The time to burn is just 10 minutes, making it crucial to take protective measures. For detailed information, you can refer to 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 16, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec171717161311121315171716
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 Weather16°C (61°F)408 mm (16.0 inches)93%extreme
February Weather16°C (61°F)401 mm (15.8 inches)92%extreme
March Weather16°C (61°F)465 mm (18.3 inches)92%extreme
April Weather16°C (61°F)282 mm (11.1 inches)90%extreme
May Weather15°C (60°F)105 mm (4.1 inches)85%extreme
June Weather15°C (59°F)40 mm (1.6 inches)70%extreme
July Weather14°C (58°F)27 mm (1.1 inches)54%extreme
August Weather15°C (58°F)64 mm (2.5 inches)44%extreme
September Weather15°C (60°F)189 mm (7.5 inches)52%extreme
October Weather16°C (61°F)299 mm (11.8 inches)65%extreme
November Weather16°C (62°F)325 mm (12.8 inches)81%extreme
December Weather16°C (62°F)325 mm (12.8 inches)89%extreme

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