September 23, 2025
Color Change: 72% (High)
Leaf Drop: Low
The Spearfish Canyon trees and flora have reached 72% of their most vibrant fall colors.
Prominent yellow leaves in the Canyon right now are from the birch trees. Birch have been captivating us all season near Savoy, but as of late we have been waiting to see those golden hues emerging south of 11th Hour Gulch. Finally today we see hints of the brilliant yellow colors to come in that area.
Prominent red leaves in the Canyon right now are from the Virginia creeper, also called five-leaf ivy. You will see this vibrant plant climbing tree trunks and spreading on the ground south of the Devil’s Bathtub parking area.
In the Sept. 18 Leaf Report, I shared one of the two most important factors that influence when leaves reach their peak: the decrease in daylight hours.
The second most important factor in the fall leaf transition is cooler temperatures. Forecasted weather for this week is warm and sunny, with daytime temperatures in the high 70s. It looks like a beautiful weather week to hike, bike, and cruise in the Canyon. The warm weather we are currently experiencing may be slowing down the leaves’ progression towards fall colors.
This month’s balminess is actually on par with what Spearfish typically experiences in the month of June. Yet in late September, it is the combination of 1) less daylight hours along with 2) cooler, longer evenings (nighttime temperatures in the 50s this week) that are signaling to the leaves it is time to prepare for winter.
