January Weather in Janesville, United States

Last updated: June 24, 2025

In Janesville, United States during January, the average temperature hovers around 0°C (32°F), with a minimum of -20°C (-4°F) and a maximum reaching 11°C (52°F). Expect a total precipitation of 102 mm (4.0 in) spread across 10 days, while maintaining an average humidity level of 86%. Stay prepared for the chill!

January Temperature in Janesville

In January in Janesville, the average temperature is 0°C (32°F). The maximum can reach 11°C (52°F), and the minimum can be as low as -20°C (-4°F). Travelers should be prepared for a wide range of temperatures and dress in layers to stay comfortable.

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

The chart illustrates January temperature patterns in Janesville, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Janesville, January typically has an average temperature of 0°C (32°F), with highs reaching up to 11°C (52°F) and lows dropping to around -20°C (-4°F).

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

January Precipitation in Janesville

In Janesville in January, the total precipitation amount is 102 mm (4.0 in) falling over the course of 10 days.

January Precipitation Trends in Janesville

The chart displays monthly precipitation patterns in Janesville, 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 Janesville, January typically receives around 102 mm (4.0 inches) of precipitation spread over approximately 10 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 Janesville

In Janesville in January humidity is 86%. With an average temperature of 0°C (32°F), this humidity feels like a biting chill that seeps into your bones, making travel feel uncomfortable and damp, as the cold air combines with the moisture to create a brisk sensation that may deter outdoor exploration.

January Average Humidity in Janesville

This chart illustrates the average monthly humidity levels in Janesville, 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 Janesville is approximately 86%, 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 Janesville

In Janesville in January, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Janesville for better planning.

Maximum UV Index Levels in Janesville for January

The chart shows the monthly maximum UV Index (UVI) for Janesville 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 Janesville typically reaches 4, which falls under the moderate exposure category.

Data source: Janesville 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 Janesville Compares to Other Months

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

This table compares monthly weather conditions in Janesville, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	0°C (32°F)	102 mm (4.0 inches)	86%	moderate
February Weather	0°C (32°F)	110 mm (4.3 inches)	87%	moderate
March Weather	2°C (37°F)	85 mm (3.4 inches)	86%	very high
April Weather	8°C (46°F)	43 mm (1.7 inches)	83%	very high
May Weather	12°C (55°F)	44 mm (1.7 inches)	72%	extreme
June Weather	19°C (66°F)	10 mm (0.4 inches)	67%	extreme
July Weather	23°C (74°F)	7 mm (0.3 inches)	56%	extreme
August Weather	22°C (72°F)	8 mm (0.3 inches)	42%	extreme
September Weather	17°C (63°F)	19 mm (0.7 inches)	46%	very high
October Weather	10°C (50°F)	34 mm (1.3 inches)	67%	high
November Weather	4°C (40°F)	47 mm (1.8 inches)	86%	moderate
December Weather	-1°C (31°F)	75 mm (3.0 inches)	86%	moderate