MINNEAPOLIS — Autumn doesn’t officially start until Sept. 22, but it already looks like the beginning of fall in parts of northern Minnesota.

The U.S. Forest Service’s regional fall color report last week singled out the Chippewa National Forest, where it said the transition already is striking: “Trees show hints of yellow, orange and red. Ash trees are usually the first to change, with a single tree turning color here or there.”

Longtime naturalist Connie Cox of Itasca State Park said the report confirms her observations — and that the changes are “a little early” but not unusual.

Brian Schwingle of the Minnesota Department of Natural Resources agreed, adding that some tree species even can show signs of change in midsummer if they are stressed. Severe drought, for example, can kick-start change.

“Plus, when we get cooler weather faster, we will see fall colors develop a little earlier,” the forest health specialist said.

Cox credits “a roller coaster” of weather beginning in late August for the early hints of fall, a key factor in the timing and pace of fall colors. A wet cycle followed by a combination of cooler nights (recent lows in the high 30s and low 40s) and summerlike daytime highs (in the 80s) have black ash and basswood trees yellowing. Pockets of red leaves are popping in some sugar maples, too. And some black cherry trees have hints of pink.

“We are cycling into fall, and it’s making its presence known very well,” she said.

The warmer weather last spring also is a contributor.

“Spring came early. Trees get tired. They have a certain duration of life in the northland,” Cox said.

Minnesota fall colors historically peak from mid-to-late September through mid-October, according to the DNR, which tracks the progression year to year. The display cascades down the state, beginning in the northwest.

The naturalist’s assessment of variable weather aligns with National Weather Service predictions: Meteorologists said there is a slim chance of snow in the Arrowhead region this week. Not unusual in border country in September, but rare this early in the month.

The DNR will issue its annual fall color report and predictions next week. Its parks and trails division devotes several webpages to maps, historical data and current conditions.

“It was a like a switch came on … a change in weather, color, animals," Cox said, noting warblers in migration and deer transitioning to winter coats. “You know, it is all weather-dependent.”

____

©2025 The Minnesota Star Tribune. Visit at startribune.com. Distributed by Tribune Content Agency, LLC.