January Weather in San Bernardino, United States

Last updated: June 24, 2025

In January, the average temperature in San Bernardino, United States hovers around 11°C (51°F), with extremes ranging from a chilly -3°C (27°F) to a warm 28°C (82°F). Expect about 70 mm (2.8 in) of precipitation over 6 days, accompanied by an average humidity of 72%. Perfect for cozy indoor activities or adventurous outings, depending on the weather!

January Temperature in San Bernardino

In January in San Bernardino, the average temperature is 11°C (51°F). Maximums can reach 28°C (82°F), and minimums can be as low as -3°C (27°F). This weather makes San Bernardino an appealing destination for travelers seeking both mild and warm conditions during their visit.

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

The chart illustrates January temperature patterns in San Bernardino, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Bernardino, January typically has an average temperature of 11°C (51°F), with highs reaching up to 28°C (82°F) and lows dropping to around -3°C (27°F).

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

January Precipitation in San Bernardino

In San Bernardino in January, the precipitation amount is 70 mm (2.8 in) over the course of 6 days.

January Precipitation Trends in San Bernardino

The chart displays monthly precipitation patterns in San Bernardino, 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 Bernardino, January typically receives around 70 mm (2.8 inches) of precipitation spread over approximately 6 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

January Humidity in San Bernardino

In San Bernardino in January, humidity is 72%. With an average temperature of 11°C (51°F), this humidity feels like a chilly dampness that clings to your skin, making traveling a bit uncomfortable and urging you to dress in layers to stay warm and dry.

January Average Humidity in San Bernardino

This chart illustrates the average monthly humidity levels in San Bernardino, 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 Bernardino is approximately 72%, 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 Bernardino

In San Bernardino in January, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in San Bernardino for better planning.

Maximum UV Index Levels in San Bernardino for January

The chart shows the monthly maximum UV Index (UVI) for San Bernardino 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 Bernardino typically reaches 4, which falls under the moderate exposure category.

Data source: San Bernardino 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 Bernardino Compares to Other Months

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

This table compares monthly weather conditions in San Bernardino, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	11°C (51°F)	70 mm (2.8 inches)	72%	moderate
February Weather	11°C (52°F)	70 mm (2.7 inches)	77%	high
March Weather	12°C (54°F)	75 mm (2.9 inches)	67%	very high
April Weather	16°C (61°F)	31 mm (1.2 inches)	56%	very high
May Weather	18°C (64°F)	18 mm (0.7 inches)	46%	extreme
June Weather	22°C (72°F)	3 mm (0.1 inches)	48%	extreme
July Weather	26°C (78°F)	11 mm (0.4 inches)	46%	extreme
August Weather	26°C (79°F)	10 mm (0.4 inches)	42%	extreme
September Weather	23°C (74°F)	10 mm (0.4 inches)	52%	very high
October Weather	19°C (66°F)	11 mm (0.4 inches)	58%	very high
November Weather	15°C (59°F)	28 mm (1.1 inches)	66%	moderate
December Weather	11°C (51°F)	70 mm (2.7 inches)	74%	moderate