Happy Fall Ya’ll, Autumnal Equinox

MADISON, Wis. (CIVIC MEDIA) – Fall of temperatures, leaves and sunlight as Mother Nature paints the landscape pretty this season, spots are already changing colors.

On Monday September 22, 2025, the seasons officially shift. It’s called the Autumnal Equinox. Where the Earth is perfectly tilted to give us equal hours of daylight and darkness. I’m sure you’ve noticed it’s darker for longer in the morning now and the sun is setting earlier too. Shorter days happen fast. In just the month of September we lose almost an hour and a half of daylight. Which is exactly why the leaves start to change colors now.

Trees are sensitive to changes in their environment. The sunlight triggers the tree to produce chlorophyll. Which is how it makes energy and why the leaves are green, a process called photosynthesis. So in summer we simply have more hours of sun available. Now, that’s being pulled away. Just like our moods may be falling with less light, foliage does too. 

Popping vibrant reds, oranges and yellows, no wonder people color chase to our Northwoods. Travel Wisconsin has an updated map of places and percentages the leaves are changing. It also forecasts a peak date, so you can set up your travel and road-trips plans ahead of time.

To see a red leaf it’s usually on maples or oaks. Which have anthocyanins turning them that color. That is also found in blueberries and cranberries, giving them that color. Carotenoids flare the orange. Like a carrot. And Xanthophylls bring the yellow leaves, in Aspen and Poplar trees and is also found in things like corn and papayas. 

As the veins from the leaf start to close off for winter, the juice retreats into the branch and shuts the door. Covering our forests and landscapes. Which the DNR says is actually beneficial, keeping the soil filled with nutrients as they decompose. 

We sure know here in Wisconsin that high winds blowing and heavy rain can easily knock them off faster. As the type of weather plays a huge part of the color change and timeframe. The National Weather Service says a drought or an early frost could make the leaves fall off of the trees before they’ve even had time to change colors.

Currently, the state is not in a drought and above average high temperatures have snuck in recently. The most stunning leaf displays follow a period of warm days filled with sunshine and cool nights for the veins to narrow and trap the sugars.

For Meteorologists, the Autumn season actually started on Labor Day, September 1st. Because it’s easier to keep track of records and changes on a 3-month basis, than on the Earth axis that wobbles. Which is exactly when some leaves started to change in our Northwoods. Peak is expected the second week of October up north. With central Wisconsin to follow and southern parts of the state closing out the month splashed in nature’s beauty.