When and where you can find peak fall foliage in Western Pa.

Parts of Somerset County are already reaching their peak fall colors, and with this week’s much-needed rain and temperatures dipping into the 40s, the rest of Western Pennsylvania won’t be far behind.

Brian Wolyniak of the Penn State Extension in Allegheny County recommends checking the Department of Conservation and Natural Resources website for timeframes for peak color, and to think about it in terms of weeks and not days.

In the eastern portions of Westmoreland County, the peak will likely happen this week.

Color across the rest of Westmoreland and Allegheny counties will follow within the next week or so, Wolyniak said.

The western part of Westmoreland County is expected to reach peak color around the third week of October, with some lower elevations holding their color through the end of the month. In Allegheny County, the best viewing time will likely be in late October.

Maple trees usually produce the most vibrant fall colors. Black cherry and birch trees, which need more water, are changing earlier than usual this year.

According to Dave Planinsek, a forester with the Pennsylvania Department of Conservation and Natural Resources in Laughlintown, Westmoreland County, oak trees tend to handle drought conditions well.

“It’s a very diverse landscape,” Planinsek said. “And every fall is different. Part of the fun this year can be looking for the colors.”

This year’s colors won’t be as vibrant.

”There wasn’t significant rainfall,” Wolyniak said. “The color will be muted because we haven’t had enough rain to keep the ground wet. Cold nights and temperatures are not so much about the color but about the timing. We will start to see lower temperatures, which can trigger the color change to start over the next few weeks.”

Ben Dunigan, director of horticulture at Phipps Conservatory and Botanical Gardens in Oakland, recalled when Keystone State Park in Derry was named by USA Today as the best destination for fall foliage in the U.S. in 2023. This year, warm temperatures didn’t allow for the chlorophyll to break down and the bright colors to emerge.

“Everyone has those spots where they know where they are, around a bend or in a park where a certain tree always looks spectacular,” Dunigan said. “There will be a little bit of a letdown this year. Just like humans, plants have to regulate their temperature.”