Winter here, in my area we get bitter cold... usually stays below -0 F for days straight. And below freezing for a week or more straight. We also get a lot of snow, at any given time we can receive up to a foot (32 cm) of snow in one day. But about 20 minutes by car from me to the east they are in a snow belt. They can receive twice as much of snow than I get but they are actually in a warmer planting zone.
There's been very different winters, especially if I compare ones of my childhood in late 80's - some of coldest in history - to recent ones, warmest in history.
First snow has usually come around Halloween, permanent snow at some point of December. January is the coldest month, can have couple weeks at -30C (though lately that's just been couple days). Finnish for January is "tammikuu"="oak month", however oak has also been called "heart tree", so the word "tammi" may have in old language meant heart, referring to "heart of winter" ("sydäntalvi" in Finnish).
February can still see cold days, but is usually much milder, with sun becoming warmer and days longer. That in Finnish is "helmikuu", "pearl month", I believe referring to ice drops and snows reflecting sunlight. Around halfway March about half of snow is gone.
For me winter is very much defined by snow. I'd say that it's winter when snow covers more than half of ground. We don't have huge amounts of snow, I don't remember ever seeing a snow cover higher than a metre or just barely over, more often half of that.
Last couple years have been first in my lifetime that there hasn't been (permanent) snow at Christmas, last year not even by new year.
And no snow here this year so far, though most of Finland has.
Temperatures hover around 5 C most of the time. Snow is fairly rare, a couple days at most in recent years. Mostly it's just slightly chilly when sitting around and occasionally precarious when the road's frozen.