Autumn is a beautiful time of year in Illinois. The red, purple, orange, yellow, brown and bronze shades of the leaves reflect the great diversity of more than 250 tree species in the state, according to the Illinois Department of Natural Resources.

However, it appears the peak of the fall color season could be delayed by the recent unseasonably warm temperatures and drought.

The peak of fall colors normally occurs by mid-October in northern and central Illinois, and by late October or early November in the southern third of the state.

Leaves change color as the duration of daylight and the angle of the sun decrease in late summer and fall. Chlorophyll production is reduced, and it begins to disappear. Carotenoids – pigments that have been present in the leaves throughout the growing season – begin to appear as yellow and orange in the leaves.

Unseasonably warm temperatures, however, can slow the transformation, which appears to be the case this season.