Despite the fact that I’m a scientist, I don’t keep a year-to-year record of leaf beauty in Colorado. I wish I had, because this year seems unusually spectacular.

Late October in my front yard.

Is it just me? Granted, I spend many days now working in my living room, where I can watch the leaves turn right outside my window. Usually, my autumn days are spent in my office – and, if I see anything outside of my window, it’s the other building. What leads to such amazing autumn colors?

A few lonely aspens near Nederland, CO.

We’ve had lots of rain this year – lots of rain through the summer. Now, we have warm days (often topping 70F), with cool nights just above freezing. Perfect recipe for autumn color.

Spectacular autumn in Northern Colorado!

For the first time since I’ve been in Colorado, I found myself raking leaves with no jacket, and trying to avoid the flowers that are still blooming in my yard. I also opened all the windows in my house to help it warm up.

I’m well aware that humans have a short-term weather and climate memory, so I made my way to the webpage of the National Weather Service in Boulder to look up some local winter weather stats. Here’s what I found:

First Freeze Last 10 Years:
October 4, 2013
October 5, 2012
October 17, 2011
October 27, 2010
October 2, 2009
October 13, 2008
October 8, 2007
September 18, 2006
October 5, 2005
October 14, 2004

As of October 23rd, I’ve had a few touches of frost in my yard. But the fact that my garden is still producing zucchini (albeit, funny-looking ones), tomatoes, and peppers, means that we haven’t had a freeze. The average date of first freeze in Denver is Oct. 7th – But note that in 2010, it didn’t occur until Oct 27th. So, perhaps this year isn’t all that unusual.

First Measurable Snow Last 10 Years:
October 18, 2013
October 5, 2012
October 25, 2011
November 15, 2010
October 21, 2009
November 14, 2008
October 22, 2007
October 18, 2006
October 10, 2005
November 1, 2004

It’s not uncommon to have the first snowfall in November. But those October events are more memorable (especially when there is snowfall while the leaves are still on the trees.) So, in short, this year may not be so different from other years – although, that still doesn’t tell us about the best leaf years. Perhaps it’s time to start keeping my own, highly subjective, record.