You’re not imagining it. This year’s fall foliage is late, and the colors that have began to pop up are not as vibrant.
The leaves’ 2021 lackluster show is one thing that can’t be blamed on the COVID-19 pandemic. Instead, pin it on climate change.
The result is that foliage predictions have been incorrect this year, which is impacting tourism in areas of the country that draw leaf peepers for annual hue-fests, including in New England, the Upper Midwest, and the Mid-Atlantic coast regions. Visitors either have come too early and are disappointed that they’re not seeing Mother Nature’s autumnal beauty, or they’re not heading to those tree hotspots at all. The charts showing when peak foliage will happen around the country have been mostly wrong this season.
“The East Coast has had an unusually warm fall,” explains Matthew Cappucci, a meteorologist based in Washington, D.C. “At this point, every month is unusually warm due to climate change. The cool season is getting both delayed and contracted. That’s combining with other factors to delay foliage.”
“Prediction maps usually take into consideration averages,” he adds. “We’re behind in averages.”
He expects foliage to hit its stride in the the next two to three weeks.
But that elongated green season impacts green of another sort. Fall foliage tourism is a $25 to $30 billion industry, according to Howard Neufeld, a professor of biology at Appalachian State University. That represents not only tours but also restaurant meals, lodging, souvenirs shopping, and other auxiliary spending.
“It’s one of the prettiest times of the year,” Neufeld says. “Trees put on a spectacular display of color. You get a kaleidoscope of color. The weather is so pleasant. People like to go out and take in these big views. They get out and get rewarded with these colors. It’s like a Jackson Pollock.”
This is how nature drips its paint on the landscape. The temperatures in September and October are critically important. The trees are taking cues from shorter days and noting the air temperature. Ideal for colorful foliage are sunny days and cool nights. Some trees, like ash, focus more on day length than on weather, while sugar maples, red maples, and black gums need the coolness.
If they’re warm, the change will be delayed because the trees will take advantage of the higher temperatures to do more photosynthesis to make sugar, according to Neufeld. When it’s cool weather, the sap turns viscous, doesn’t move from the leaf, and builds up there. The stuck sugar makes the red pigment. In contrast, the orange and yellow colors are already in the leaf but covered up by the tree’s chlorophyll, so when the chlorophyll breaks down in autumn, those two hues appear.
“As you get climate change, you delay the onset of colors, and when they do come out, at least the reds, they’re not as bright,” Neufeld adds, explaining that recent daily temperature lows are what the highs should be.