January Weather in Walnut Creek, United States

Last updated: June 24, 2025

In January, the average temperature in Walnut Creek, United States is a chilly -1°C (31°F). Temperatures can vary significantly, with minimums reaching -21°C (-5°F) and maximums soaring to 21°C (70°F). Additionally, expect 88 mm (3.5 in) of precipitation spread over 11 days, and brace yourself for a high average humidity of 88%.

January Temperature in Walnut Creek

In January in Walnut Creek, the average temperature is -1°C (31°F). The maximum can reach 21°C (70°F), while the minimum can be as low as -21°C (-5°F). This variation in temperatures makes it essential for travelers to pack appropriately for both warmer days and frigid nights.

January Weather in Walnut Creek: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Walnut Creek, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Walnut Creek, January typically has an average temperature of -1°C (31°F), with highs reaching up to 21°C (70°F) and lows dropping to around -21°C (-5°F).

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

January Precipitation in Walnut Creek

In Walnut Creek in January, the total precipitation amount is 88 mm (3.5 in) spread over 11 days.

January Precipitation Trends in Walnut Creek

The chart displays monthly precipitation patterns in Walnut Creek, 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 Walnut Creek, January typically receives around 88 mm (3.5 inches) of precipitation spread over approximately 11 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 Walnut Creek

In Walnut Creek in January, humidity is 88%. With an average temperature of -1°C (31°F), this humidity feels like a biting cold that penetrates your clothing, making outdoor exploration challenging and the air clingy, adding an extra chill that can make you feel even colder than the temperature suggests.

January Average Humidity in Walnut Creek

This chart illustrates the average monthly humidity levels in Walnut Creek, 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 Walnut Creek is approximately 88%, 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 Walnut Creek

In Walnut Creek in January, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Walnut Creek, you can check the information here.

Maximum UV Index Levels in Walnut Creek for January

The chart shows the monthly maximum UV Index (UVI) for Walnut Creek 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 Walnut Creek typically reaches 3, which falls under the moderate exposure category.

Data source: Walnut Creek 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 Walnut Creek Compares to Other Months

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

This table compares monthly weather conditions in Walnut Creek, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-1°C (31°F)	88 mm (3.5 inches)	88%	moderate
February Weather	1°C (34°F)	106 mm (4.2 inches)	88%	moderate
March Weather	5°C (42°F)	103 mm (4.1 inches)	87%	high
April Weather	11°C (51°F)	129 mm (5.1 inches)	87%	very high
May Weather	17°C (63°F)	122 mm (4.8 inches)	81%	very high
June Weather	22°C (71°F)	126 mm (5.0 inches)	83%	very high
July Weather	24°C (76°F)	118 mm (4.7 inches)	82%	very high
August Weather	23°C (73°F)	86 mm (3.4 inches)	76%	very high
September Weather	20°C (68°F)	105 mm (4.2 inches)	77%	very high
October Weather	14°C (57°F)	109 mm (4.3 inches)	82%	high
November Weather	5°C (42°F)	94 mm (3.7 inches)	89%	moderate
December Weather	2°C (36°F)	95 mm (3.8 inches)	86%	low