Last updated: June 24, 2025
In Naperville, United States, the average temperature in September hovers around 20°C (68°F), providing a pleasant climate for outdoor activities. However, temperatures can vary significantly, with a minimum of 2°C (36°F) and a maximum of 34°C (93°F). Expect 95 mm (3.8 in) of precipitation spread over about 10 days, contributing to an average humidity of 80%. Embrace the diverse weather while enjoying all that Naperville has to offer!
In September in Naperville, the average temperature is 20°C (68°F), with maximums reaching up to 34°C (93°F) and minimums dropping as low as 2°C (36°F). This diverse range of temperatures makes Naperville an ideal destination for travelers seeking both warm days and cool evenings.
In Naperville in September, the precipitation amount is 95 mm (3.8 in) over the course of 10 days.
In Naperville in September, humidity is 80%. With an average temperature of 20°C (68°F), this humidity feels like traveling through a warm, dense blanket that clings to your skin, making you feel both sticky and lethargic as you explore the sights.
In Naperville 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 Naperville.
UV Risk Categories
Weather in Naperville varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Naperville, focusing on differences in temperature, rainfall, humidity, and UV levels.
Temperature | Precipitation | Humidity | UV | |
---|---|---|---|---|
January Weather | -4°C (26°F) | 62 mm (2.5 inches) | 82% | moderate |
February Weather | -3°C (28°F) | 63 mm (2.5 inches) | 83% | moderate |
March Weather | 4°C (40°F) | 87 mm (3.4 inches) | 84% | high |
April Weather | 9°C (49°F) | 117 mm (4.6 inches) | 85% | very high |
May Weather | 16°C (61°F) | 157 mm (6.2 inches) | 79% | very high |
June Weather | 22°C (72°F) | 152 mm (6.0 inches) | 82% | very high |
July Weather | 24°C (76°F) | 119 mm (4.7 inches) | 80% | very high |
August Weather | 23°C (73°F) | 91 mm (3.6 inches) | 81% | very high |
September Weather | 20°C (68°F) | 95 mm (3.8 inches) | 80% | very high |
October Weather | 12°C (54°F) | 129 mm (5.1 inches) | 82% | high |
November Weather | 4°C (39°F) | 57 mm (2.3 inches) | 88% | moderate |
December Weather | 0°C (33°F) | 53 mm (2.1 inches) | 84% | low |