REGIONAL— An unusual fall color season appears headed toward a second climax by this weekend, after a mid-September burst of color generally faded away earlier than usual.
According to the Department of Natural Resources, the fall color was ranging from 25-75 percent across northern St. Louis County, a pace of change that is well behind last year and somewhat behind the color change in 2022.
The record warm temperatures this September likely delayed the onset of the color change and the lack of rainfall is expected to lead to a more muted color change than in most years. Many trees, including maple and some birch and aspen, turned early this year, then dropped their leaves, leaving some stands nearly bare, while others continued to hold green leaves. The sunny days and cooler nights this week should spark a second peak as those remaining green leaves are rapidly turning now and could be close to peak by this weekend.
State parks are a good place to view the fall colors and this weekend’s forecast for more sunshine and high temperatures in the low 60s should make for perfect conditions for outdoor activities. As of Oct. 1, the DNR was reporting 25-50 percent color change at Lake Vermilion Soudan Underground Mine State park and 50-75 percent at Bearhead Lake State Park.
The recent chilly nights combined with the abundant sunshine are helping spark the change. That’s because the chlorophyll that gives leaves their green color breaks down in the fall, and cooler temperatures at night and sunshine during the day tend to speed up that process. As the chlorophyll breaks down, other phytochemicals, like carotenoids and anthocyanins, which reflect yellows, oranges, and reds, come into the foreground, giving leaves their “fall” color.