January Weather in San Francisco, Peru

Last updated: August 27, 2025

In January, the average temperature in San Francisco, Peru is a comfortable 20°C (69°F). You can expect temperatures to dip to a minimum of 17°C (62°F) and peak at a warm 25°C (78°F). However, be prepared for some moisture, as precipitation averages 73 mm (2.9 in) over approximately 17 days. With an average humidity of 89%, it's a great time to enjoy the unique climate of this locale!

January Temperature in San Francisco

In January in San Francisco, the average temperature is 20°C (69°F). The maximum can reach 25°C (78°F), and the minimum can be as low as 17°C (62°F). This comfortable climate makes San Francisco an ideal destination for travelers looking to enjoy pleasant weather during this time.

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

The chart illustrates January 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, January typically has an average temperature of 20°C (69°F), with highs reaching up to 25°C (78°F) and lows dropping to around 17°C (62°F).

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

January Precipitation in San Francisco

In San Francisco in January, the precipitation amount is 73 mm (2.9 in) over the course of 17 days.

January Precipitation Trends in San Francisco

The chart displays monthly precipitation patterns in San Francisco, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In San Francisco, January typically receives around 73 mm (2.9 inches) of precipitation spread over approximately 17 days.

Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

January Humidity in San Francisco

In San Francisco in January humidity is 89%. With an average temperature of 20°C (69°F), this humidity feels like a warm blanket enveloping you, making outdoor activities uncomfortable and requiring frequent breaks for hydration and rest.

January Average Humidity in San Francisco

This chart illustrates the average monthly humidity levels in San Francisco, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in San Francisco is approximately 89%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in San Francisco

In San Francisco in January, 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 January

The chart shows the monthly maximum UV Index (UVI) for San Francisco in January, 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 January, the maximum UV index in San Francisco typically reaches 15, which falls under the extreme exposure category.

Data source: San Francisco January 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 January 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 January’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 January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	20°C (69°F)	73 mm (2.9 inches)	89%	extreme
February Weather	21°C (69°F)	84 mm (3.3 inches)	89%	extreme
March Weather	21°C (70°F)	58 mm (2.3 inches)	90%	extreme
April Weather	20°C (68°F)	20 mm (0.8 inches)	89%	extreme
May Weather	19°C (66°F)	4 mm (0.2 inches)	83%	extreme
June Weather	18°C (65°F)	1 mm (0.1 inches)	69%	very high
July Weather	18°C (64°F)	1 mm (0.0 inches)	56%	extreme
August Weather	18°C (64°F)	0 mm (0.0 inches)	50%	extreme
September Weather	18°C (64°F)	2 mm (0.1 inches)	53%	extreme
October Weather	18°C (65°F)	5 mm (0.2 inches)	68%	extreme
November Weather	19°C (66°F)	5 mm (0.2 inches)	81%	extreme
December Weather	19°C (67°F)	13 mm (0.5 inches)	87%	extreme