January Weather in Eureka, United States

Last updated: June 24, 2025

In Eureka, United States, the average temperature in January hovers around -10°C (15°F). However, be prepared for extreme variations, as minimum temperatures can plummet to -35°C (-31°F), while the maximum may reach up to 8°C (47°F). Expect about 14 mm (0.6 in) of precipitation over 3 days, with an average humidity of 81%, creating a truly wintry experience.

January Temperature in Eureka

In January in Eureka, the average temperature is -10°C (15°F). Maximum temperatures can reach 8°C (47°F), while minimums can plummet to -35°C (-31°F). Travelers should prepare for a wide range of temperatures and dress in layers to stay comfortable during their visit.

January Weather in Eureka: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Eureka, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Eureka, January typically has an average temperature of -10°C (15°F), with highs reaching up to 8°C (47°F) and lows dropping to around -35°C (-31°F).

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

January Precipitation in Eureka

In Eureka in January, the precipitation amount is 14 mm (0.6 in) accumulated over the course of 3 days.

January Precipitation Trends in Eureka

The chart displays monthly precipitation patterns in Eureka, 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 Eureka, January typically receives around 14 mm (0.6 inches) of precipitation spread over approximately 3 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 Eureka

In Eureka in January humidity is 81%. With an average temperature of -10°C (15°F), this humidity feels like a biting frost that clings to your skin, making travel uncomfortable and chilly, as the cold air sharpens with every breath.

January Average Humidity in Eureka

This chart illustrates the average monthly humidity levels in Eureka, 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 Eureka is approximately 81%, 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 Eureka

In Eureka in January, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Eureka, you can visit Hourly UV Index in Eureka.

Maximum UV Index Levels in Eureka for January

The chart shows the monthly maximum UV Index (UVI) for Eureka 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 Eureka typically reaches 2, which falls under the low exposure category.

Data source: Eureka 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 Eureka Compares to Other Months

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

This table compares monthly weather conditions in Eureka, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-10°C (15°F)	14 mm (0.6 inches)	81%	low
February Weather	-11°C (13°F)	17 mm (0.7 inches)	85%	moderate
March Weather	-1°C (30°F)	29 mm (1.1 inches)	76%	moderate
April Weather	4°C (40°F)	43 mm (1.7 inches)	79%	high
May Weather	13°C (56°F)	57 mm (2.2 inches)	76%	very high
June Weather	21°C (70°F)	59 mm (2.3 inches)	81%	very high
July Weather	23°C (74°F)	63 mm (2.5 inches)	82%	very high
August Weather	21°C (70°F)	102 mm (4.0 inches)	82%	very high
September Weather	16°C (62°F)	69 mm (2.7 inches)	77%	very high
October Weather	7°C (44°F)	63 mm (2.5 inches)	76%	moderate
November Weather	0°C (32°F)	14 mm (0.5 inches)	84%	moderate
December Weather	-6°C (22°F)	27 mm (1.1 inches)	81%	low