ST. LOUIS– One of the highlights of the autumn season is the leaves changing beautiful shades of golds, oranges, and reds. Now that it’s officially fall, the mild days and chilly nights will accelerate the fall colors across the country.
As the country heads into later September and early October, the colors will reach a peak starting from the north to the south.
By October 18, most of the country will be seeing peak fall colors. That is according to data courtesy of smokeymountain.com and its foliage predictor map.
By November 1, most of the country will be past the peak for fall colors.
Here is when different parts of the U.S. could see peak or near peak fall colors:
- Sept. 20- Montana, Wyoming, Colorado, Utah, Minnesota
- Sept. 27-Additionally, Idaho, New Mexico, North Dakota, Minnesota, Michigan, Maine, Vermont, New Hampshire, Massachusetts, Virginia, West Virginia
- Oct. 4- Additionally, parts of Washington, Oregon, Arizona, South Dakota, Iowa, New York, Conneticut, Rhode Island, Kentucky, Tennessee, North Carolina, South Carolina, Georgia
- Oct. 11- Additionally, parts of Illinois, Arkansas, Indiana, Ohio, Pennsylvania, New Jersey, Texas
- Oct. 18- Additionally, parts of Missouri, Nebraska, Kansas, Alabama
- Oct. 25- Addiotionally, parts of Oklahoma, Mississippi
The timing and quality of these colors are impacted yearly by the weather. Not only the fall weather leading up to it but the summer weather as well.
“A lot of it has to do with just the overall health of the tree and that is always tied to the weather. So a tree that’s been through a lot of heat stress and drought stress isn’t going to have the same energy reserves and the same compounds built up inside of itself to make that really brilliant color,” said Aaron Lynn-Vogel, horticulture answer service coordinator at the Missouri Botanical Garden.
On average, summer heat stress and drought would lead to an earlier and less impressive fall color season. This summer we haven’t technically been in a drought, but we have certainly had some difficult stretches of hot weather.
To ensure good color this year we can hope for nice, sunny autumn days so the trees still have plenty of light to make into food and gradually cooling nights.
Leaves are full of chlorophyll for most of their lifespan, which keeps them green. That chlorophyll is turned off as trees start to go dormant for the winter.
“You don’t want to have a really quick freeze because this will just damage all of the leaves before they have a chance to draw out that chlorophyll and then they just turn a crummy brown,” Lynn-Vogel said. “And you don’t want it to stay too hot for too long because of the opposite side of that. The leaves just stay green for much longer and you don’t get the same development of those colors as they withdraw the chlorophyll.”