The drought stress may not necessarily trigger an early leaf change, but rather an extended period of time to view the fall foliage, said Brian Wolyniak, an urban and community forest educator at Penn State University.

The appearance of the trees in the region will depend heavily on how much rainfall a given area has received, he said, as well as how drought-tolerant each species of tree is.

Rain in late September helped to slow the color transition for many forests in Pennsylvania, for instance, which had been facing drought stress, according to the state’s Department of Conservation and Natural Resources.

“The rainfall and warm nighttime temperatures likely stabilized the fall color timeline, which had been significantly advanced,” the agency said in a report.

However, the expected cooldown over the weekend should stimulate noticeable color changes across the state, according to DCNR.

The Clinton County service forester in Central Pennsylvania called this year a “strange” time for foliage, adding that the late summer drought caused many of the maples and birches in the Bucktail Natural Area to prematurely drop their leaves, and that the most colorful species have “quickly passed peak.”

Foresters are currently reporting the most spectacular autumn foliage in northern parts of Pennsylvania. Meanwhile, the William Penn State Forest in southeastern Pennsylvania is starting to see early changes to fall color among its red maple, sycamore and black gum.

“It may be a little bit more dull than what we’ve seen in other years, but despite the conditions, we’ll still be able to have some of that color and enjoy it, maybe just not the brightest version of it,” said Penn State’s Wolyniak. “And maybe the silver lining is we have maybe a little bit more extended time to view it because of these drier conditions.”