Average date of first snowfall for Mt. Mansfield in Vermont

Having recently picked up our first snowfall of the season here in Vermont, reports and discussion in the New England Regional Forum at American Weather had people wondering where this event sat with respect to the average date of occurrence for the first snowfall on Mt. Mansfield.  I’d been curious about that date as well, so I used the data from the Mt. Mansfield co-op weather observations site, which comes from the ridgeline of the mountain up near the 4,000-foot elevation.  It’s a fairly substantial data set that goes all the way back to 1954, and Wesley Wright set it up to be available through the SkiVT-L site at UVM.

“The data suggest that our first snow of the 2018-2019 winter season from this past Saturday (October 13th) is a few days on the late side of the mean for first accumulating snow (October 10th), but overall quite typical.”

There are a couple of seasons that I couldn’t include in the statistical analysis because of gaps in the data collection early in the co-op site’s history, but there were still 62 seasons in the data set that provided useful information.  The data suggest that our first snow of the 2018-2019 winter season from this past Saturday (October 13th) is a few days on the late side of the mean for first accumulating snow (October 10th), but overall quite typical.  The full results from the statistical analysis are below, so have a look and think snow!

Date of 1st Accumulating Snow at Mt. Mansfield, VT Co-Op Station:

Mean:  10/10
Median:  10/8
Mode:  10/17
S.D.:  15 days
n:  62
Earliest:  8/28/1986
Latest:  11/17/1985