January Weather in Eureka, United States

Last updated: June 24, 2025

In January, the average temperature in Eureka, United States hovers around -3°C (27°F). While it can dip as low as -30°C (-22°F), the mercury can also rise to a maximum of 15°C (59°F). Expect about 61 mm (2.4 in) of precipitation spread over 8 days, with an average humidity level of 82%, making it a chilly and damp time of year.

January Temperature in Eureka

In January in Eureka, the average temperature is -3°C (27°F). Maximums can reach 15°C (59°F), while minimums can drop as low as -30°C (-22°F). Travelers should be prepared for a wide range of temperatures when visiting during this time.

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 -3°C (27°F), with highs reaching up to 15°C (59°F) and lows dropping to around -30°C (-22°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 61 mm (2.4 in) distributed over 8 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 61 mm (2.4 inches) of precipitation spread over approximately 8 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 82%. With an average temperature of -3°C (27°F), this humidity feels like a biting chill that seeps into your bones, making traveling uncomfortable and necessitating extra layers to stay warm while navigating through the damp air.

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 82%, 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 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 Eureka, you can check the information here.

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 3, which falls under the moderate 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	-3°C (27°F)	61 mm (2.4 inches)	82%	moderate
February Weather	-2°C (29°F)	68 mm (2.7 inches)	83%	moderate
March Weather	5°C (42°F)	106 mm (4.2 inches)	84%	high
April Weather	10°C (51°F)	117 mm (4.6 inches)	85%	very high
May Weather	18°C (64°F)	165 mm (6.5 inches)	79%	very high
June Weather	23°C (74°F)	138 mm (5.4 inches)	82%	extreme
July Weather	25°C (77°F)	109 mm (4.3 inches)	80%	very high
August Weather	23°C (74°F)	80 mm (3.1 inches)	81%	very high
September Weather	21°C (70°F)	69 mm (2.7 inches)	80%	very high
October Weather	13°C (56°F)	130 mm (5.1 inches)	82%	high
November Weather	4°C (40°F)	56 mm (2.2 inches)	88%	moderate
December Weather	1°C (34°F)	55 mm (2.2 inches)	84%	low