The effects of drought will be evident this fall when Colorado’s leaf-peeping season arrives early with a color change that is less vibrant than in years with normal or above-average levels of precipitation.
“When water is in short supply, trees shut down and prepare for the winter season on an accelerated timeline,” said Barbara Demmig-Adams, a University of Colorado professor and an expert on leaf pigments. “They drop their leaves early, with leaf edges turning brown especially quickly.”
The experts at the Colorado Parks and Wildlife department who monitor foliage that wildlife eat are already seeing this happen, said spokesperson Bridget O’Rourke.
“Because of the wildfires and the drought, animals are dealing with limited habitat. Things just started drying up,” O’Rourke said. “That means the leaves, when it comes for their final beautiful breath before they die, there’s not as many leaves out there that are actually going to be changing colors. They’re just going to be drying up and falling.”
O’Rourke said she expects trees in Colorado’s alpine terrain to start changing by mid-September and be completely done by mid-October, depending on the region. When the aspens hit peak, they will be bright gold for a shorter period of time, she said.
In the summer, trees’ leaves are green because of the chlorophyll they use to collect and process nutrients via photosynthesis. Chlorophyll contains nitrogen, which trees transfer and store in their roots in the fall before dropping their leaves. The removal of chlorophyll allows carotenoid, or yellow, pigments to show right before the leaves die, said Demmig-Adams.
Last winter’s record-low snowpack and the subsequent drought will hasten that process not only at high elevations, but also lower ones, Demmig-Adams added. That includes in Denver where the oaks and maples usually turn later in the fall.
Fall colors: Here’s the science behind the reds, golds and oranges
As of Aug. 11, was experiencing some level of drought, according to the U.S. Drought Monitor. About 14% was listed as experiencing “exceptional drought” — the highest level — including mountainous areas such as all of Eagle County, Pitkin County, and Lake County.
If all this sounds familiar, that's because Colorado was in a similar, though less severe, situation last summer when about 70% of the state was experiencing drought, per U.S. Drought Monitor. Compare that to 2023, described by one local expert as a “banner year” for leaf-peeping when just 28% of the state was in drought, and itap easy to see the correlation between moisture and fall colors.
That doesn't mean it won't be worth getting out there to enjoy the changing of seasons. In fact, there are a whole host of scenic drives and hikes we'd recommend. Heck, take some PTO and you could chart an entire road trip inspired by leaf-peeping.
Those looking for guidance on when the foliage will peak can use 2025 as a loose reference, accounting for the fact that drought is worse this year.
Mountains in the northern part of the state often peak first; last year, the expected peak was around Sept. 20. Colors in the central mountains — Summit County, Eagle County and the Interstate 70 corridor — popped off around the last weekend of September, while the southern mountains peaked in early October.
As the color change gets underway, locals can also follow the for real-time updates. If you plan to visit a state park, O'Rourke recommends calling ahead of time to ask a ranger for status updates.
Trees and bushes aren’t the only parts of nature that depend on water. Wildlife may also be extra protective around their natural resources this year, O’Rourke said. She cautioned leaf-peepers to be careful not to get too close to moose in wetlands or elk during the rut. Bears are also much more active this year, as the drought has diminished natural food sources.
“We, unfortunately, see elk and moose attacks every single fall. If itap going to be limited water resources, itap safe to say they’ll be even more sensitive this fall,” O’Rourke said.
Also, be sure to adhere to continued forest closures where wildfires took place this summer and check the appropriate U.S. Forest Service district website where you want to visit for the latest information.
