Is Maine’s foliage peaking later as falls get warmer?

Maine’s Autumn Colors Shift to a New Rhythm, Experts Say

In a state long celebrated for its crimson and gold foliage, the calendar of fall has begun to shift. Recent research and long‑term state reporting show that the peak of leaf color in Maine’s forests is arriving later each decade, while the weather on any given fall can still swing the timing dramatically from year to year.

The Long‑Term Trend

Geographer Stephanie Spera of Acadia National Park has traced the pattern of the park’s autumn colors using satellite imagery, historical photographs, and ranger notes that go back more than sixty years. Her analysis shows that the peak foliage at Acadia, which lies in the state’s Zone 2 map, arrived about nine to ten days later in 2026 than it did in the 1950s. The delay averages roughly one day per decade.

Spera notes that Acadia has warmed 3.4 °F over the past century, a rise that is mirrored across Maine’s forests. The park’s botanical inventory has also changed: one in five plant species documented a hundred years ago are no longer present, and seven of the ten most common tree species are projected to decline or potentially vanish by 2100.

What Drives the Shift?

The change is not simply a matter of warmer air. While higher temperatures slow the breakdown of chlorophyll and keep leaves green later into October, other factors—rainfall patterns, soil moisture, and pest outbreaks—also play a major role. The Maine Climate Council warns that future seasons will see “more droughts and deluges play out in the same calendar year,” adding to the volatility.

Seasonal variability is already evident in the weekly reports filed by state forest rangers, a system that began in 1959 and was the first in the country to post such data online (in 1996). Those reports, which track the progression of foliage across Maine’s seven zones, have revealed “wild swings” from early peaks driven by summer droughts to late or uneven peaks caused by fungal blights and heavy fall rains.

In 2020, a severe summer drought pushed more than half of the state’s zones to peak in late September—an early date that would not reappear until six years later. By contrast, years with late, warm falls sometimes see the foliage arrive in mid‑October.

Economic and Cultural Impact

Maine’s leaf‑peeping season is a major driver of tourism, pumping nearly half a billion dollars into the state’s economy each fall. While the exact timing of the peak can influence travel patterns, the overall volume of visitors is largely resilient. Still, businesses—ranging from roadside stands to guided tours—pay close attention to the ranger maps and satellite feeds, which now show a trend toward later peaks.

“The people who love Maine’s fall colors are watching the data closely,” says a representative of the Maine Tourism Association. “If the season shifts even a week, that can affect everything from lodging bookings to harvest festivals.”

A New Baseline

The state’s forest rangers have been gathering weekly foliage updates for over 60 years. Initially transmitted by radio to the state headquarters and then relayed to local newspapers, the reports became the first publicly available weekly data set on forest health in the United States. The shift to a web‑based system in 1996 has turned the data into a real‑time marketing tool as well as a scientific record.

Looking ahead, climate models predict that the “climate personality” of Maine’s forests will continue to push peak colors deeper into the calendar. Although the variability from year to year will still be pronounced, the baseline trend suggests a gradual delay of a day or more per decade.

In the Classroom

While students at Bates College study the science behind the changing colors, they also take time to unwind. One student, Annie Holub, was photographed mid‑sudoku on the Lewiston campus quad, surrounded by the very foliage she will soon see shift in color.

Maine News Now will keep track of the state’s ongoing changes and bring you the latest updates on how climate change is reshaping one of the region’s most cherished natural spectacles.