January Weather in Grinnell, United States

Last updated: June 24, 2025

In Grinnell, United States, the average temperature in January hovers around -6°C (22°F), with extremes ranging from a brisk -31°C (-24°F) to a milder 14°C (57°F). Visitors should prepare for occasional precipitation, averaging 43 mm (1.7 in) over about 6 days, and expect a noteworthy average humidity of 78% throughout the month.

January Temperature in Grinnell

In January in Grinnell, the average temperature is -6°C (22°F), with maximums reaching 14°C (57°F) and minimums dropping as low as -31°C (-24°F). Travelers should be prepared for extremely cold conditions and sudden temperature fluctuations.

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

The chart illustrates January temperature patterns in Grinnell, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Grinnell, January typically has an average temperature of -6°C (22°F), with highs reaching up to 14°C (57°F) and lows dropping to around -31°C (-24°F).

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

January Precipitation in Grinnell

In Grinnell in January, the precipitation amount is 43 mm (1.7 in) over a period of 6 days.

January Precipitation Trends in Grinnell

The chart displays monthly precipitation patterns in Grinnell, 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 Grinnell, January typically receives around 43 mm (1.7 inches) of precipitation spread over approximately 6 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 Grinnell

In Grinnell in January, humidity is 78%. With an average temperature of -6°C (22°F), this humidity feels like a biting chill that seeps through your layers, making outdoor activities less enjoyable and creating a sharp contrast that can be unexpectedly uncomfortable for travelers.

January Average Humidity in Grinnell

This chart illustrates the average monthly humidity levels in Grinnell, 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 Grinnell is approximately 78%, 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 Grinnell

In Grinnell 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 Grinnell, you can check the information here.

Maximum UV Index Levels in Grinnell for January

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

Data source: Grinnell 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 Grinnell Compares to Other Months

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

This table compares monthly weather conditions in Grinnell, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-6°C (22°F)	43 mm (1.7 inches)	78%	moderate
February Weather	-5°C (23°F)	48 mm (1.9 inches)	80%	moderate
March Weather	4°C (39°F)	79 mm (3.1 inches)	77%	high
April Weather	9°C (49°F)	81 mm (3.2 inches)	77%	very high
May Weather	17°C (62°F)	166 mm (6.5 inches)	77%	very high
June Weather	23°C (74°F)	133 mm (5.2 inches)	81%	extreme
July Weather	24°C (76°F)	81 mm (3.2 inches)	81%	very high
August Weather	23°C (73°F)	71 mm (2.8 inches)	77%	very high
September Weather	20°C (68°F)	118 mm (4.7 inches)	73%	very high
October Weather	11°C (53°F)	145 mm (5.7 inches)	75%	high
November Weather	3°C (38°F)	46 mm (1.8 inches)	85%	moderate
December Weather	-1°C (31°F)	38 mm (1.5 inches)	83%	moderate