Does Snow in October Mean We're in for a Tough Winter?

Snowy October scene from U.S. Forest Service webcam
Snowy scene near Boundary Waters on October 27, 2017.
Courtesy: U.S. Forest Service
 

When snows come early in Minnesota, winter-lovers rejoice, but those who resent the cold season may start to feel dread. So, do early snows tell us anything about the coming winter?

In short, no. It appears that an October snow is just an October snow, and has no bearing on the remainder of winter. Through 2016, 44 out of 140 Octobers in the Twin Cities have seen at least one day with measurable snow. The winters that followed those instances of snowfall have spanned nearly the entire spectrum of possibilities: dry, wet, snowy, cold, warm, and of course, average. In northern Minnesota, where October snows occur most years, the range of winter conditions after those snows is even wider.

Even a persistently snowy autumn cannot promise us a brutal remainder of winter. In 1991, both Duluth and the Twin Cities had more autumn snow than any other year on record, by wide margins. November was the 12th coldest on record in Duluth and the 7th coldest in the Twin Cities. The remainder of winter, however, was a far cry from what we would have expected: snowfall from December onward ranked 93rd at both locations, and the December through February period was 17th warmest at Duluth and 11th warmest in the Twin Cities. Indeed, winters immediately following a snowy fall can be just about anything.

The following table summarizes the fifteen snowiest autumn seasons in the Twin Cities, along with a look at what the remainder of each winter was like. It is clear that getting measurable snow early in the season tells us little if anything about the rest of the cold weather season!

 

Table of 15 highest snowfall totals through November in the Twin Cities, with snowfall and temperature stats for the remainder of winter.
RankSnow through November (in.)YearSnow, December Onward (Rank) Average Temperature, December - February (deg. F) (Rank, coldest)
 1 55.1 1991 29.0      (93)23.7                   (135)
 2 30.4 1983 68.2      (11)14.3                     (43)
 3 26.3 194026.2    (104)18.1                     (93)
 4 24.3 198545.2      (44)13.6                     (34)
 5 21.8 1947 27.3      (99)14.6                     (46)
 6 19.7 1886 42.6      (51)5.8                       (2)
 7 17.0 190528.1      (97)20.1                   (113)
 816.8 199656.8      (20)14.6                     (46)
 9 16.6 192126.7    (101)15.3                     (57)
 10 16.5 1978 51.9      (26)9.4                       (8)
 11 16.2 1975 37.1      (66)20.2                   (114)
 12 16.0 198854.0      (25)16.8                     (75)
 13 14.9 198180.1        (3)11.9                     (19)
 14 14.7 197736.0      (70)10.5                     (12)
 15 14.1 189848.3      (36)11.9                     (19)

 

 

Last modified: October 27, 2017
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