What parts of Pennsylvania are seeing peak color? Here’s an update on this fall’s foliage

Those hoping to see the beautiful colors offered by autumn in Pennsylvania will want to get out and about this week, when peak color is expected in Centre County and much of state.

The Pennsylvania Department of Conservation and Natural Resources expects the most robust fall foliage in the northern and central parts of the state now through at least Oct. 19, with a few exceptions.

The agency says color is already starting to fade in Wayne, Susquehanna, Potter and McKean counties, though many southern counties will see the best color in the coming weeks.

The Smoky Mountains Fall Foliage Prediction Map, which covers the continental U.S. and is monitored by many forestry officials, predicts color in the state is a bit more advanced, with some of the state already considered past peak as of Oct. 17.

The map uses data from the National Oceanic and Atmospheric Administration and is interactive.

For those who prefer a more old fashioned foliage prediction, the Farmers’ Almanac projects peak time for leaf color in the Keystone State to last through midweek, until at least Oct. 21.

Pennsylvania’s 2022 fall foliage outlook

While the prime window to view the fall colors has largely arrived, those out looking may find the canopy a bit spottier than expected, according to Julianne Schieffer, an extension urban forester with the Penn State Extension.

In a late September interview, she noted dry weather – particularly conditions that resulted in a drought watch being issued for 36 counties earlier this fall – could result in fewer leaves on trees by the time peak colors arrive.

“There are just, plain and simple, less leaves on the trees,” she told the Centre Daily Times. “… It’s just going to be a little bit more spotty, I think, and a little bit more see-through.”

That premature leaf drop and early yellowing, particularly among the maples, is an adaptation to the environmental conditions that allows the tree to better prepare for the coming winter.

Despite some potential for spottiness, Schieffer noted Pennsylvania’s range of tree species provide a lush array of fall colors. Dogwoods, sassafras and smaller species are usually the first to turn in the state, she said, while tulip poplars and oaks are some of the final leaves to turn.

Pennsylvania is home to 130 native species of tree.

What causes the leaves to change in the fall?

The turning of the leaves from lush greens to an array of autumnal tones is an outward display of the tree’s preparation for winter.

Chlorophyll, the green pigment leaves display in spring and summer, produces food for the trees by photosynthesizing sunlight and carbon dioxide. Less sunlight in the fall triggers the preparation for winter and the end of chlorophyll production. The green that masked other pigments fades to allow a bounty of autumn colors.

Beta-carotene and xanthophyll give off yellows, oranges and browns while anthocyanin results in reds and purples.

The leaf colors are also affected by weather and sunlight.

Associate teaching professor of meteorology Bill Syrett with Penn State also noted the effect of the summer’s dry conditions on fall colors – “regular precipitation is good for the tree health and the leaf health.”

Warm autumn days paired with cool nights can also boost colorful foliage, but the summer’s dry weather was not ideal.

“Much of northeastern Pennsylvania is 3 to 6 inches below average for the summer” in terms of rainfall, he noted in late September. It wasn’t extreme drought, “but enough to stress some of the weaker trees.”

Best spots to catch fall foliage in Pennsylvania

State tourism officials are counting on the explosion of fall colors to bring leaf-peepers to many parts of Pennsylvania. Among the sites they’ve advertised is Rothrock State Forest in State College, where hikers, cyclists and more can see what the Seven Mountains area has to offer.

Those headed south to catch peak colors later in October might consider Gettysburg National Military Park, where you can see the fall leaves from a guided horseback tour.

If you’re in or exploring the northern parts of the state, you might consider Ricketts Glen State Park, where you can take in the foliage along with the sights of 22 named waterfalls.

According to a Sept. 22 release from DCNR, fall tourism in Pennsylvania infuses $45 billion into the economy and results in $5 billion in tax revenues while helping support as many as 500,000 jobs across the commonwealth.