Fall is here

KMSP - A lot of folks have been asking me why the leaves are changing so early this year.  My answer to them has been, they really aren’t.  Yes, I suppose that the metro may be a few days ahead of schedule, but it’s really negligible.  So why does it feel like they are changing so much earlier this year?  My guess is because they have been so far behind for the last several years.  The last couple of years specifically, the leaves have been delayed in their fall brilliance by a couple of weeks or more for one reason or another.  That reason isn’t always a bad thing.  In fact, in 2014 and 2015 it was because we had seen so much rain that the trees were reluctant to begin their changeover so they could take advantage of the wet weather.  This year though, they are arguable a few days early, which combined with last year’s lateness, puts them a good 3 weeks ahead of when we remember them changing. 

Why so early this year? Well, a couple of reasons.  Precipitation has been fairly normal and reasonably regular this year, until the first half of this month when the rain pretty much shut off.  That can often be a sign to the trees that fall is fast approaching because it is a much drier season on average.  Also, this was the coolest August since 2004. Just like humans, trees “remember” recent trends the most, and the last several Augusts have been very very warm.  After those warm Augusts, the first couple of freezes came before the trees were ready, launching them into slumber much faster than is healthy for them, just to protect themselves from the suddenly cooler temps.  As weird as it sounds, they actually remember that stuff (it’s not clear how).  So, when we cooled off in August, the trees thought it was time to start getting ready for winter.

As for timing this year, we should be right on target, or even a few days early for some.  That would put northern Minnesota at peak in just a couple short weeks, with the rest of the state not far behind.