We all know that leaves change their colors in the fall, making this time of year a favorite for its spectacular colors. But what causes the leaves to turn?
In autumn, the days get shorter and the temperatures get cooler. The sun doesn’t warm the leaves as directly or intensely as it did during spring and summer. In these shorter, cooler days, the process of making food within the leaves ceases. As this occurs, the leaves use the food they’ve stored throughout the summer. This causes the leaves’ green pigment to become less dominant and gives other colors an opportunity to be displayed.
Weather affects both the leaves’ color intensity and duration. Ideal conditions for spectacular coloring are a warm, dry summer followed by a rainy autumn. In autumn, warm, sunny days with cool nights trigger brilliant color formations. An early frost lessens the intensity of red. Rainy or overcast days intensify the brilliancy of color. A cool, clear day is always best for viewing.
Planning a trip to see fall foliage in all its glory? The Farmers’ Almanac predicts fall color will be at its peak during these times:
Sept. 28-Oct. 8: Vermont (northern)
Sept. 28-Oct. 29: New York, depending on elevation and distance from coast
Oct. 5-15: Colorado, Maine (inland), Michigan (northern), Minnesota (northern), Montana (central), New Hampshire (inland), New Mexico, Vermont (southern), Wisconsin, Wyoming
Oct. 12-22: Arizona, Idaho, Illinois (northern), Indiana (northern), Iowa, Kentucky (eastern), Maine (coastal), Massachusetts (inland), Michigan (southern), Minnesota (northern), Missouri (northern), Montana (western), New Hampshire (coastal), North Dakota, Ohio, Pennsylvania, South Dakota, Utah, West Virginia,
Oct. 19-29: Arkansas (Ozarks), California (northern), Connecticut, Illinois (southern), Indiana (southern), Kentucky (western), Maryland (inland), Massachusetts (coastal), Missouri (southern), New Jersey (inland), North Carolina (inland), Oregon, Rhode Island, Tennessee, Virginia (inland), Washington
Oct. 26-Nov. 5: Alabama, Arizona, Arkansas, Delaware, Georgia (northern), Maryland (coastal), Mississippi (northern), New Jersey (coastal), North Carolina (coastal), South Carolina, Virginia (coastal)
(Note that peak times are earlier at higher elevation.)