MINNEAPOLIS (WCCO) — Scientists know that it’s the amount of daylight that triggers the leaves to start changing.
Less sun means less green chlorophyll, which means the yellows, browns and oranges start peeking through.
That happened mostly on time this year. What’s different is how quickly the leaves turned once they started.
A Minnesota Department of Natural Resources map shows much more red and dark red compared to Sept. 30 in 2019 and 2018.
Forest health experts tell WCCO there are a few reasons for this fall’s speedy colors. Over the summer, there wasn’t as much rain as usual up north. That means the soil isn’t as moist, which means the trees are somewhat stressed — and stressed trees change colors more quickly.
The opposite happened in southeastern Minnesota. They had more rain than usual, which also stresses the trees.
Another factor is that it’s been a little colder up north. That can also cause the reds to really come out. Duluth saw its first hard freeze on Sept. 18.
On the DNR’s map, peak is defined as the percentage of trees that have changed colors. Past peak means the leaves have dropped to the ground. The map comes from reports from 75 different parks and recreation centers across the state. They have to update at least once a week, but some do more than others, and that changes the map right away.
Check back every few days, because this time of year it all happens faster than most of us would like.
Some of the best fall colors are popping right now just north and west of the Twin Cities.