September weather forecast and climate
Illinois, USA

September brings the beautiful fall season to Illinois with comfortable conditions and dazzling colors. The daily sunlight of 8 hours peaks in the afternoon, while the humidity is at the highest in the mornings. The average temperatures are in the pleasant 50°F (10°C) to 80°F (26.7°C) range across the state, with 3" (76mm) to 4" (102mm) of rainfall.
The maples, elms, and walnuts change colors by mid-September as the landscape assumes a fairyland look. By the end of September, the hues are prominent with brilliant shades of red, orange, yellow, purple, and magenta. An autumn weekend is ripe to experience a fall color festival. Colors run amok from rural farming towns to urban metropolitan areas and their suburbs. Fall evenings are perfect for romantic settings in a natural environment untouched by time.
Light jackets provide comfort during the breezy evenings, while t-shirts are suitable during the day when the temperatures are high. September is one of the best times to visit Illinois.