December Weather in Rockford, United States

Last updated: June 24, 2025

In December, the average temperature in Rockford, United States hovers around -2°C (28°F), but be prepared for a wide range as the minimum can drop to -22°C (-7°F) while the maximum may reach 21°C (70°F). During this period, expect around 36 mm (1.4 in) of precipitation spread over 5 days, with the air holding an average humidity of 83%. Be ready for a mix of chilly days and unexpected warmth!

December Temperature in Rockford

In December in Rockford, the average temperature is -2°C (28°F). Maximum temperatures can reach 21°C (70°F), while minimums can drop to as low as -22°C (-7°F). Therefore, travelers should be well-prepared for a wide range of weather conditions during their visit.

December Weather in Rockford: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Rockford, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Rockford, December typically has an average temperature of -2°C (28°F), with highs reaching up to 21°C (70°F) and lows dropping to around -22°C (-7°F).

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

December Precipitation in Rockford

In Rockford in December, the precipitation amount is 36 mm (1.4 in) over the course of 5 days.

December Precipitation Trends in Rockford

The chart displays monthly precipitation patterns in Rockford, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In Rockford, December typically receives around 36 mm (1.4 inches) of precipitation spread over approximately 5 days.

Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

December Humidity in Rockford

In Rockford in December, humidity is 83%. With an average temperature of -2°C (28°F), this humidity feels like a biting chill that penetrates your clothes, making outdoor activities uncomfortable and travel challenging.

December Average Humidity in Rockford

This chart illustrates the average monthly humidity levels in Rockford, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Rockford is approximately 83%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Rockford

In Rockford in December, 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 Rockford, you can check the information here.

Maximum UV Index Levels in Rockford for December

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

Data source: Rockford December 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 December Weather in Rockford Compares to Other Months

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

This table compares monthly weather conditions in Rockford, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-7°C (20°F)	39 mm (1.5 inches)	82%	moderate
February Weather	-7°C (19°F)	48 mm (1.9 inches)	84%	moderate
March Weather	2°C (36°F)	74 mm (2.9 inches)	80%	moderate
April Weather	8°C (46°F)	77 mm (3.0 inches)	81%	very high
May Weather	16°C (61°F)	162 mm (6.4 inches)	74%	very high
June Weather	22°C (73°F)	128 mm (5.0 inches)	80%	extreme
July Weather	24°C (75°F)	97 mm (3.8 inches)	80%	very high
August Weather	22°C (71°F)	115 mm (4.5 inches)	77%	very high
September Weather	19°C (66°F)	101 mm (4.0 inches)	75%	very high
October Weather	10°C (50°F)	125 mm (4.9 inches)	80%	moderate
November Weather	2°C (36°F)	49 mm (1.9 inches)	87%	moderate
December Weather	-2°C (28°F)	36 mm (1.4 inches)	83%	moderate