Chicagoland autumn foliage expected to begin in late September

In the Chicagoland area, autumn foliage is expected to begin changing in late September. According to Spencer Campbell, Senior Manager of Natural Areas at The Morton Arboretum, the transition is driven by bright, sunny days and cool nights, specifically around 50 degrees Fahrenheit.

The seasonal display varies by species: sumac shrubs typically change first in September, followed by maples with orange and yellow hues. The season reaches its peak with oaks in mid-October or November, and the display generally continues until the first or second week of November.