September Weather in Rockford, United States

Last updated: June 24, 2025

In September, the average temperature in Rockford, United States hovers around 19°C (66°F). Expect a range where the minimum can dip to 2°C (36°F) and the maximum may soar to 33°C (92°F). During this month, the area sees approximately 101 mm (4.0 in) of precipitation spread over 10 days, coupled with a notable average humidity of 75%.

September Temperature in Rockford

In September in Rockford, the average temperature is 19°C (66°F). The maximum can reach 33°C (92°F) and the minimum can be as low as 2°C (36°F). This diverse climate makes Rockford an ideal destination for travelers looking to experience a range of temperatures and activities.

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

The chart illustrates September 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, September typically has an average temperature of 19°C (66°F), with highs reaching up to 33°C (92°F) and lows dropping to around 2°C (36°F).

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

September Precipitation in Rockford

In Rockford in September, the precipitation amount is 101 mm (4.0 in) spread over the course of 10 days.

September Precipitation Trends in Rockford

The chart displays monthly precipitation patterns in Rockford, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Rockford, September typically receives around 101 mm (4.0 inches) of precipitation spread over approximately 10 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Rockford

In Rockford in September humidity is 75%. With an average temperature of 19°C (66°F), this humidity feels like a warm, enveloping blanket, making it slightly uncomfortable for traveling as you navigate through the thick, muggy air.

September Average Humidity in Rockford

This chart illustrates the average monthly humidity levels in Rockford, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Rockford is approximately 75%, offering insight into how humid the weather typically is during this month.

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

September UV Index in Rockford

In Rockford in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Rockford.

Maximum UV Index Levels in Rockford for September

The chart shows the monthly maximum UV Index (UVI) for Rockford in September, 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 September, the maximum UV index in Rockford typically reaches 8, which falls under the very high exposure category.

Data source: Rockford September 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 September 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 September’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 September’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