Winter Begins:
A) First day with high temp below 32F (0C), or
B) First measurable snowfall, or
C) December 1st
Winter Ends:
A) Last day with high temp below 32F (0C), or
B) Last measurable snowfall, or
C) Snow depth = 0, or
D) March 1st
Legend (Days):
- Over 225
- 200 to 225
- 180 to 200
- 160 to 180
- 140 to 160
- 120 to 140
- 90 to 120
- 90
From the author:
Length of winter during 1981-2014 time period. Data from Global Historical Climatology Network (GHCN) utilized. A total of 946 stations had sufficient data for inclusion in the analysis. The definition of when winter begins and ends is on the map. Every possible definition has flaws.
Personally, I really like this map, especially growing up in Ottawa where winters felt like they went forever.
That said, I do think the part using dates as part of the criteria is a little odd. By doing so it means no location has a winter length of less than 90 days.
On the the other hand, with global warming winters would sort of start and stop based on a purely temp and snowfall based criteria.
The biggest example of this to me personally was that Ottawa’s Rideau Canal, didn’t open for a single day of skating in 2023. When I was growing up you’d typically get at least 40 days of skating (with a record 69 days in 2000) and it was not uncommon for it to open before Christmas.
How has winter changed over the last few decades where you live?
Y.D. Robinson says
It’s really not necessarily appropriate to say that there’s catastrophic man-made global warming just because winters are markedly warmer than a few decades ago. The operative thing is to compare with winters of thousands, or tens of thousands, or millions of years ago. There have been warm periods at various points even just during the past 10,000 years (never mind millions upon millions of years ago) when winters – and the entire climate – were as warm as today or even warmer.
As an example, there is scientific evidence that the Medieval Warm Period was at least as warm as today over the entire world, not just in Europe and the North Atlantic. If the Rideau Canal had been built already by then, there might very well have been many winters – most probably in a row – in which it wouldn’t have been frozen enough to go skating over.
It’s important to get all the facts about past and present weather/climate, not just from those proclaiming catastrophic man-made climate change.