January Weather in Spearfish, United States

Last updated: June 24, 2025

In January, the average temperature in Spearfish, United States hovers around -3°C (26°F), with extremes ranging from a chilling -30°C (-22°F) to a mild 14°C (57°F). Expect about 22 mm (0.8 in) of precipitation spread across 6 days, while the air tends to be quite moist, with an average humidity of 77%. Prepare for a winter wonderland!

January Temperature in Spearfish

In January in Spearfish, the average temperature is -3°C (26°F). The maximum can reach 14°C (57°F), and the minimum can drop to as low as -30°C (-22°F). For travelers, this month offers a unique blend of cold weather that requires proper preparation and layering for outdoor activities.

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

The chart illustrates January temperature patterns in Spearfish, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Spearfish, January typically has an average temperature of -3°C (26°F), with highs reaching up to 14°C (57°F) and lows dropping to around -30°C (-22°F).

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

January Precipitation in Spearfish

In Spearfish in January, the total precipitation amount is 22 mm (0.8 in) over the course of 6 days.

January Precipitation Trends in Spearfish

The chart displays monthly precipitation patterns in Spearfish, 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 Spearfish, January typically receives around 22 mm (0.8 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 Spearfish

In Spearfish in January humidity is 77%. With an average temperature of -3°C (26°F), this humidity feels like a biting chill that seeps into your bones, making it feel significantly colder than the actual temperature, which can dampen the joy of outdoor exploration and lead to discomfort if not properly prepared.

January Average Humidity in Spearfish

This chart illustrates the average monthly humidity levels in Spearfish, 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 Spearfish is approximately 77%, 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 Spearfish

In Spearfish 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 Spearfish, you can check the information here.

Maximum UV Index Levels in Spearfish for January

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

Data source: Spearfish 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 Spearfish Compares to Other Months

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

This table compares monthly weather conditions in Spearfish, 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 (26°F)	22 mm (0.8 inches)	77%	moderate
February Weather	-6°C (21°F)	33 mm (1.3 inches)	80%	moderate
March Weather	2°C (35°F)	39 mm (1.5 inches)	70%	high
April Weather	5°C (41°F)	74 mm (2.9 inches)	70%	very high
May Weather	11°C (52°F)	98 mm (3.9 inches)	76%	very high
June Weather	19°C (66°F)	65 mm (2.6 inches)	84%	extreme
July Weather	22°C (72°F)	88 mm (3.4 inches)	85%	extreme
August Weather	20°C (69°F)	58 mm (2.3 inches)	84%	very high
September Weather	16°C (61°F)	43 mm (1.7 inches)	77%	very high
October Weather	7°C (44°F)	65 mm (2.5 inches)	73%	moderate
November Weather	3°C (37°F)	21 mm (0.8 inches)	74%	moderate
December Weather	-1°C (30°F)	31 mm (1.2 inches)	79%	low