Winter Weather in Big Snow Country: a lot of Snow but Little Extremely Cold Weather

The true Northern style winter is about 4 months long, from about November 20 until about March 20. But winter can be up to 4 1/2 months long in a more severe than usual winter. On the other hand, global warming may produce some winters that are effectively shorter, down to say 3 1/2 months.

Global warming can possibly extend a mix of rain and light snow well into December, as it did in two recent years. If this happens, since a normal December by itself produces on average 1/4 of annual snow, the overall snow for the year will most likely end up to be much less than usual.

In almost all years, at least 90% of the snow falls between November 20 and March 20. It snows much more in the first two of those four months. The average date when half of all snow for the season has fallen is no later than January 10. The rate of snow drops off by half or more whenever Lake Superior becomes substantially frozen over, which it often but not always does between very late January and early February.

For how much snow falls and typical snow depths, see this article.

COLDEST MONTHS OF ALL
During much of the coldest two months of winter, running from December 25 until about February 25, the temperature remains at or below freezing 24 hours a day, which causes the snow to pile up much more than it would if there were a good number of days above freezing. During these coldest 60 days, you typically will get only about eight days when the temperature reaches 33 degrees or higher.

In a colder than normal January, it will rise above freezing (32 degrees) during the day only one or two times the whole month. In a normal January, the high temperature will be a little above freezing three or four times on the average. Except in a really cold January, there will be at least one day in January when the high temperature is at least 40, but rarely will a January day be any warmer than 42.

The temperature remains below freezing all day more than 75% of the days during most December-February periods. In typical winter months, the temperature will rise above freezing between three and five days during January and during February, and five or six days in December, mostly in the first half of December.

THE THREE COLDEST MONTHS: DECEMBER--FEBRUARY
Everyone knows there is a lot of snow in the winter in Big Snow Country. What most people don't know is that in the winter it is actually a little warmer here than it is south and west of here. The overall average winter temperature in Big Snow Country (December through February) is about equal to the average winter temperature in Minneapolis-St. Paul, which is 200-300 miles southwest of Big Snow Country. Most people don't know this and would not think it to be true. The overall average winter temperature in both the Twin Cities and in Big Snow Country is about 17 degrees.

Even more surprising is that the most severe cold snaps are actually substantially worse in the Twin Cities than they are in Big Snow Country. This is because Lake Superior modifies even severe cold to make it somewhat less severe. In the most severe cold snaps, happening between once and three times a year, the temperatures in the Twin Cities will be about four or five degrees colder than they are in Big Snow Country. The more minor cold snaps are going to be a degree or two worse in Minneapolis-St. Paul than they are in and Big Snow Country.

THE COLDEST WEATHER OF ALL
The most extreme cold periods happen either once, twice, or if you are not lucky three times between late December and the first few days of March. These outbreaks of true arctic air in Big Snow Country cause the day highs to be between zero and ten above zero, and the night lows to be between fifteen below and five below. These outbreaks last from two to six days.

These cold waves are not as severe as they are more than 30 miles from Lake Superior. These cold periods are from 3-25 degrees less extreme in Big Snow country than they are in all of Minnesota, than they are North and South Dakota, and than they are in all of Wisconsin except for right along the Lake Michigan shore and except for the southeast area.

Looking more generally at all winter days that are below normal, within 30 miles of Lake Superior, the nights are substantially warmer (5-25 degrees) while days are between 15 degrees warmer and 5 degrees colder than they are in those other areas.

THE ABSOLUTE COLDEST NIGHTS OF THE YEAR
The coldest handful of nights / mornings of the year are never as severely cold in Big Snow Country as they are away from the lake. To be specific, unlike in the Dakotas, unlike in Minnesota including the Twin Cities, and unlike in Wisconsin away from Lake Michigan, the temperature in Big Snow Country drops below minus 10 degrees only between once and four times a year. You can count on mornings of less than minus 10 three to fifteen times per year in those other areas.

In most years, the temperature never drops below minus 15 degrees in Big Snow Country, whereas it can easily drop to minus 20, to minus 30, or even to minus 40 (North Dakota) in those other areas.

So it is quite rare for the temperature to ever drop below minus 15 degrees. The absolute coldest night / morning of the year will most years end up being between minus 11 and minus fifteen degrees, which is about 5 degrees WARMER than the usual coldest night /morning in the Twin Cities.

MEDIAN ABSOLUTE COLDEST DAY OF THE YEAR IN BIG SNOW COUNTRY: NOT THE AVERAGE TEMPERATURES BY ANY STRETCH!
The first number is the average morning low of the coldest day of the year and the second number is the average afternoon high.

Copper Harbor -8/3
Calumet-Laurium -13/1
Houghton -14/1
South Range-15/1
Painesdale -16/1
Ontonagon -10/3
Ironwood -16/2
Marquette -15/3
Munising -15/3

FOR COMPARISON
Twin Cities, Minnesota -20/0
Wausau, Wisconsin -18/0
Fargo, North Dakota -25/-5
Winnipeg, Canada -33/-13

THE SHORE VERSUS 5-30 MILES INLAND ON THE COLDEST 2-3 MORNINGS OF THE YEAR
On the coldest mornings of all, the night / morning lows are going to be about four degrees colder at Houghton than they are at Copper Harbor. Specifically, in the most severe arctic waves, which normally occur once or twice a year, at Houghton the lows will be between -10 and -15, whereas the lows at Copper Harbor will hold to between -6 and -11. In slightly higher terrain south of Houghton, at South Range for example, the coldest mornings of the year will be between -12 and -17. To the southwest, the coldest mornings of the year are slightly colder due to specific topographical features. There you can look for the coldest mornings to be between -13 and -18 at Ironwood and between -15 and possibly -20 at Wakefield.

Meanwhile, at Marquette lake shore, the coldest mornings of the year are going to be between -10 and -15 degrees. The coldest mornings of the year are up to three degrees colder 5-10 miles inland (-13 to -18) and another degree colder still by the time you get to Negaunee (-14 to -19). Michigamme, the principal town in western Marquette County is in a higher, farther from the lake, semi-wilderness area where the coldest mornings of the year are between -18 and -23 degrees.

BIG SNOW COUNTRY COLDEST 2-3 NIGHTS / MORNINGS OF THE YEAR
The coldest night of the year will often feature morning lows in the following range:

Copper Harbor -6 to -11
Calumet-Laurium -10 to -15
Houghton -10 to -15
South Range-11 to -16
Painesdale -12 to -17
Ontonagon -7 to -12
Wakefield -15 to -20
Ironwood -13 to -18
Champion -17 to -22
Negaunee -14 to -19
Marquette lakeshore -10 to -15
Marquette inland area -13 to -18
Munising -10 to -15

COLDEST NIGHTS / MORNINGS ELSEWHERE
Big Snow Country is the counties along Lake Superior in Michigan. Just to the south of Big Snow Country, the coldest mornings are much colder. For example, at Iron Mountain MI, expect the coldest two or three mornings of the year to be between -20 and -27 degrees. More comparisons:

WISCONSIN COLDEST 2-3 NIGHTS / MORNINGS OF THE YEAR
Rhinelander -18 to -25
Wausau -15 to -22
La Crosse -14 to -21
Madison -11 to -18

MINNESOTA COLDEST 2-3 NIGHTS / MORNINGS OF THE YEAR
International Falls -29 to -36
Duluth -17 to -24
St. Cloud -19 to -26
Twin Cities -14 to -21
Rochester -14 to -21

NORTH DAKOTA COLDEST 2-3 NIGHTS / MORNINGS OF THE YEAR
Grand Forks -24 to -31
Fargo -20 to -27
Bismarck -20 to -27

SOUTH DAKOTA COLDEST 2-3 NIGHTS / MORNINGS OF THE YEAR
Aberdeen -18 to -25
Huron -16 to -23
Sioux Falls -12 to -19

MANITOBA COLDEST 2-3 NIGHTS / MORNINGS OF THE YEAR
Winnipeg -27 to -34

DAILY AVERAGES AT HOUGHTON-HANCOCK
You can see the exact average highs and lows for Houghton-Hancock for every day of the year. You will find them here.

For details about the weather between March 20 and November 20, see this article.