According to www.currentresults.com/ Boulder’s first autumn snowfall may arrive as early as September or as late as November. October is more likely than not to receive at least two inches of snow. The season’s final snowfall falls in April or May. From June to August, Boulder is normally snow-free.

Most snowfall days in Boulder leave at least an inch of fresh snow on the ground. On average, three inches or more of new snow falls on 12 days per year.  Snowfalls of more than five inches per day are common six times a year.  On average, one of those days will include a major blizzard with a snowfall of ten inches or more.

First Snowfall in Boulder: 

2000   September 23
2001   October    5
2002   October   23
2003   October   30
2004   November   1
2005   November  15
2006   October   10 
2007   October   21
2008   October   13
2009   October   10
2010   November   9
2011   October   26
2012   October    5
2013   October    4
2014   September 12
2015   November 11
2016   November 17
2017   October 5
2018   October 10
2019   October 10
2020   September 8
2021   November 24