Last updated: June 24, 2025
In September, the average temperature in Sycamore, United States is a pleasant 20°C (68°F). However, be prepared for some variation, as temperatures can dip to a minimum of 5°C (41°F) and soar up to a maximum of 34°C (93°F). Expect about 73 mm (2.9 in) of precipitation over 9 days, with an average humidity of 78%. Whether you're soaking up the sun or enjoying a refreshing rain shower, there's something for everyone!
In September in Sycamore, the average temperature is 20°C (68°F). Maximums can reach 34°C (93°F) and minimums can be as low as 5°C (41°F). Travelers should be prepared for warm days and cool nights, making layering essentials for this time of year.
In Sycamore in September, the precipitation amount is 73 mm (2.9 in), occurring over the course of 9 days.
In Sycamore in September humidity is 78%. With an average temperature of 20°C (68°F), this humidity feels like a warm, enveloping blanket that makes exploring the sights a bit sticky, so travelers should stay hydrated and take frequent breaks in the shade.
In Sycamore 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 Sycamore.
UV Risk Categories
Weather in Sycamore varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Sycamore, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -2°C (30°F) | 72 mm (2.9 inches) | 88% | moderate |
| February Weather | 0°C (32°F) | 89 mm (3.5 inches) | 87% | moderate |
| March Weather | 5°C (41°F) | 97 mm (3.8 inches) | 87% | high |
| April Weather | 10°C (50°F) | 110 mm (4.3 inches) | 87% | very high |
| May Weather | 17°C (62°F) | 134 mm (5.3 inches) | 81% | very high |
| June Weather | 22°C (71°F) | 131 mm (5.1 inches) | 82% | very high |
| July Weather | 24°C (75°F) | 123 mm (4.8 inches) | 81% | very high |
| August Weather | 23°C (73°F) | 86 mm (3.4 inches) | 78% | very high |
| September Weather | 20°C (68°F) | 73 mm (2.9 inches) | 78% | very high |
| October Weather | 14°C (57°F) | 93 mm (3.7 inches) | 82% | high |
| November Weather | 5°C (42°F) | 90 mm (3.5 inches) | 89% | moderate |
| December Weather | 2°C (35°F) | 70 mm (2.7 inches) | 86% | low |