Snow Depth Days
of the Northeast: 2017-2018

The season in review

November was quiet, as was most of December except for some nice size storms on the 9th and 12th. Christmas Day brought a regime change. After the biggest snow storm of the month, cold air blew in bringing sub-zero temps from through Jan 7th, except for the 26th (1.5°F) and 4th (1.8°F). Most of the rest of January was much warmer, with essentially three thaws, the first with a high temperature of 55.6°F on the 12th and six other days over 45°F.

Daily/Monthly Data

The following table summarizes the snow fall and depth days from sites that are posting that data on local weather observations mail lists and a couple others. If people also prepare Web pages for daily information for their site, I'll include links to them. Cells under the "snow" column are the snowfall for the site in that month, under "SDD" are the depth days for the month.

Location October November December January February March April May
Snow SDD Snow SDD Snow SDD Snow SDD Snow SDD Snow SDD Snow SDD Snow SDD
Fairhaven MA 6.7 15 11.5 41
Pepperell MA 0.1 0 15.8 121 18.6 172
Poland Spring ME 1.2 1 29.6 203 18.8 347
Bow NH 22.3 165.5 15.6 296
Bristol NH 2.3 1.9 28 216 13.3 374
Deerfield NH 22 203
Penacook NH 0.9 0.5 24.9 181 12.1 280
Mt. Mansfield VT 2 2 22.1 186 33.3 888 9 1231

2017-2018 season to end of last month

The persistence quotient is lower than the ultimate value if there is still snow on the ground at the site. This data will be updated each month.

Location Snowfall Depth Days Persistence
Fairhaven MA 18.2 56 3.1
Pepperell MA 34.5 293 8.5
Poland Spring ME 49.6 551 11.1
Bow NH 37.9 461.5 12.2
Bristol NH 43.6 591.9 13.6
Deerfield NH 22 203 9.2
Penacook NH 37.9 461.5 12.2
Mt. Mansfield VT 66.4 2307 34.7


Name Location
Dennis Bollea Fairhaven MA
Wayne Cotterly Poland Spring ME
Robert Davitt Deerfield NH
Steve Gunn Bristol NH
Jim Hilt Bow NH
Andrew Plona Collinsville CT
Paul Venditti Pepperell MA
Ric Werme Penacook NH


Jim Corbin, a meteorologist from Rhode Island, proposed the concept of both snow depth days and the persistence quotient, but he didn't have good names for them.  After a bouncing around various ideas, I came up with Depth Days.  It seems to fit into colloquial speech well, e.g. "When mired in the Depth Days of February, she thought fondly of the Dog Days of August." Of course, none of us snow lovers would ever think that. I picked Persistence Quotient while putting this page together, we'll see how it wears with time.


I think depth days is a great statistic, and I'm surprised that it is catching on slowly outside of the NE Weather Spotters mail list. I never expected that the NWS would embrace it quickly, but I had hoped that TV meteorologists would start using it, in monthly summaries, if nothing else. It would be nice if ski areas would use it, but they may not wish to if they are not likely to be #1 consistantly. (And if only one area reports depth days, it would not be a good comparative statistic.) The University of Vermont has graphs of snow depths at Stowe through many seasons.

Last update: 2018 February 4
Ric Werme

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