September Weather in Rockford, United States

Last updated: June 24, 2025

In September, the average temperature in Rockford, United States hovers around 20°C (69°F), offering a pleasant climate for various activities. Temperatures can range from a chilly 4°C (39°F) to a warm 33°C (91°F), so be prepared for anything! Expect an average precipitation of 70 mm (2.8 in) over about 8 days, with humidity levels around 78%, adding a tropical feel to your stay.

September Temperature in Rockford

In September in Rockford, the average temperature is 20°C (69°F). The maximum can reach 33°C (91°F), while the minimum can drop as low as 4°C (39°F). This variation in temperature makes Rockford a versatile destination for travelers seeking both warm days and cool evenings.

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 20°C (69°F), with highs reaching up to 33°C (91°F) and lows dropping to around 4°C (39°F).
JanFebMarAprMayJunJulAugSepOctNovDec293241516372767368574135
Data source: Temperature data for Rockford generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Rockford

In Rockford in September, the total precipitation amount is 70 mm (2.8 in), spread over the course of 8 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 70 mm (2.8 inches) of precipitation spread over approximately 8 days.
JanFebMarAprMayJunJulAugSepOctNovDec75841009212812410910370938364
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Rockford

In Rockford in September, humidity is 78%. With an average temperature of 20°C (69°F), this humidity feels like a warm, enveloping blanket, making travel somewhat uncomfortable as sweat clings to your skin and the air feels thick and heavy, urging you to seek out shaded areas and refreshing drinks.

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 78%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%87%87%88%81%82%81%78%78%82%89%86%
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.
JanFebMarAprMayJunJulAugSepOctNovDec356910101098642
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.
 TemperaturePrecipitationHumidityUV
January Weather-2°C (29°F)75 mm (2.9 inches)88%moderate
February Weather0°C (32°F)84 mm (3.3 inches)87%moderate
March Weather5°C (41°F)100 mm (3.9 inches)87%high
April Weather10°C (51°F)92 mm (3.6 inches)87%very high
May Weather17°C (63°F)128 mm (5.1 inches)81%very high
June Weather22°C (73°F)123 mm (4.9 inches)82%very high
July Weather24°C (76°F)109 mm (4.3 inches)81%very high
August Weather23°C (74°F)103 mm (4.0 inches)78%very high
September Weather20°C (69°F)70 mm (2.8 inches)78%very high
October Weather14°C (57°F)93 mm (3.7 inches)82%high
November Weather5°C (42°F)83 mm (3.3 inches)89%moderate
December Weather2°C (35°F)64 mm (2.5 inches)86%low

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