DAYTON, Ohio (WDTN) – As the season changed from summer to fall across the Miami Valley, a few trees have began to transition. The weather has been a large contributing factor to the vibrancies of fall foliage.
Leaves begin to change color when they lack sufficient sunlight.
When the color changes, it stops the food making process. The green pigment in a plant, called chlorophyll, breaks down and allows the yellow and red colors to pop in the fall skyline.
However, sunlight is only part of the equation, with weather playing a large role in how vivid the foliage will be.
“The most vibrant of all colors are brought about by warm, sunny days and the cool, clear night times, and certainly the past three or four weeks we’ve gotten exactly that across much of the Ohio Valley,” said Kristen Cassady, meteorologist, National Weather Service in Wilmington.
September has been a dry month, but the summer has had near-normal numbers for precipitation, promoting good tree health. In turn, more vibrant colors take over the autumn leaves.
“You don’t want to get too dry. It’s always a balance of, you know, soil conditions and weather conditions,” Cassady said. “Then the leaves can start to dry out and fall prematurely. But I think we’ve got a good mixture thus far of good soil conditions and good temperatures as well.”

Heading into early October, the Miami Valley will be set up in a pattern that will promote warmer-than-normal temperatures and drier-than-normal conditions, which are all favorable conditions for optimal fall colors. Most of the Miami Valley will see the peak colors around mid to late October.
One concern every year is the risk of a wind storm before the peak fall colors, knocking leaves off their branches pre-maturely.