I'll go with Jim's formula but will use to published official averages from the closest weather station:

December to March, days with average highs below 0C:
December: 16.4
January: 21.4
February: 17.8
March: 9.6
Total (overall) days below 0C = 70.2
Average number of lows below -20C= 12.7
-30C= 0.58

Wow. I'm in a pretty cold area!

Here's mine from the other post-

How about total days below freezing high temps(32F)
below 20F for highs
below 10
below 0(F)

11 days with 0(F) or below/low temps/lowest was -12(F)

Warmest day(in March) 64F. We were also 61F on Dec 1, 2009

Let's look at last winter here.

Starting Dec 1 2009-March 20th
33F/or less highs total-70
20F or less highs total-12
10F or less highs total-3

24 days above freezing(12 were in March!)
so half of those 24 days were in March after the snow melted.
and hows this for a turnaround?

Starting May 22-78 days in a row 80F or warmer and 50 days 90F or warmer!

I bet this winter is a shocking contrast from last-to the good!

Oops... I thought it said "coolest poster" I can't do any good here. 😀

Paul, I can't resist these climate discussions! 😆

There would be many ways to tackle this question of the coldest. There's a guy who's looked at the climate data of Calgary, Edmonton, Winnipeg since 1979.
Basically, since 1979 (I would say a very reasonable sample for determining zone) Calgary has been 4a and Edmonton and Winnipeg 3b. I actually posted this data here, in another forum.

http://palmsnorth.com/forum/viewtopic.php?t=2524&highlight=

Here's the zone data, if you care:

http://forums.northscaping.com/post?id=2654415

Another approach might simply be average annual temp.-in which case the cities you listed would rank as follows:

Kingston: 44f
Calgary: 40f
Edmonton: 37f
Winnipeg: 37f
Thunder Bay: 36f

Source: Weatherbase

Here's Calgary's stats, the way you guys chose to look at it:

December to March, days with average highs below 0C:
December: 14.4
January: 16.0
February: 11.7
March: 8.5
Total (overall) days below 0C = 63.4
Average number of lows below -20C= 26.0
-30C= 4.8

Interestingly, Calgary is very different from all of these cities, in terms of winter though. We always see at least 10c in every month of the winter, and usually around 15c-even in January (because of our Chinooks). This is, of course, not altogether good for many plants as we often see our coldest temps. with little or no snow cover (I really think many yuccas are an exception to this rule, hence my interest in cultivating them here) We are a cold semi-desert. Despite my frustration towards our climate, in terms of plants, I think it's one of the most comfy climates for humans, in Canada. One of the better in a sorry lot, IMO! I'll take most of our winter over, for example, Vancouver's any day. That stuff is cold! I don't care if you can technically golf in it!

BTW Paul, I think that minimum for Calgary was recorded by the Mounties who settled the city 😉 ! -40c has not happened in my, not so short, life time. The rule of thumb here is we don't get much above 30c, or below -30c. Having said all that, I think Calgary might just be coldest place in terms of sustaining many of the plants people grow on this forum (most yuccas, I would say, being an exception). Cowtown lacks summer heat and is overall just incredibly erratic (as you can see in the above data: higher winter highs and lower lows than a place like Kingston). Well there's my two cents.

Thanks!

Duncan

Friday's Vancouver "Province" newspaper "Brace Yourself for a Wicked Winter" might reduce those lows even further.

The newspaper adds "Forecasters are warning us to expect our worst (winter) weather in 55 years", under La Nina, reported by Washington state climatologist Nick Bond.

http://www.climate.washington.edu/outlook.html

Canadian meteorologists must be asleep? 😆 😆
Barb

Boy-o-boy those are some COLD temps.

Guys, when you are counting days below zero do you mean the day (sunrise - sundown) temperature or over the entire twenty-four hours one?

Sorry, guys, but I'm excited. This link says I have a 40% chance of warmer-than-normal temps the next three months!

igor, welcome to Palms North.
We'd love to see some photos of what you're growing.

Minimum temps are the coldest temperature, normally at night.

I haven't seen our temperature records broken down by how many hours it stayed that cold.
Or how many hours it stayed at the maximum for the day.

Erik, wow, that'll get you almost to end of January.
Those plants may not need to go into the ballroom, after all.
Barb

Igor,
please forgive my earlier rudeness in my excitement about the weather here.

Welcome! I have not been to Kazakhstan, but my brother and his wife have had the pleasure and talk about the natural beauty of the moutains.
My assumption is that you could grow Nannorrhops palms with some winter protection. Is that correct?
--Erik

Here's some neat stats for Canada:

Most days below -20C:
http://www.climate.weatheroffice.gc.ca/winners/categorydata_e.html?SelectedCategory=11

Most freezing days:
http://www.climate.weatheroffice.gc.ca/winners/categorydata_e.html?SelectedCategory=8

Most extreme wind-chill days (-30C)
http://www.climate.weatheroffice.gc.ca/winners/categorydata_e.html?SelectedCategory=67

Sunniest winter:
http://www.climate.weatheroffice.gc.ca/winners/categorydata_e.html?SelectedCategory=42

Snowiest cities:
http://www.climate.weatheroffice.gc.ca/winners/categorydata_e.html?SelectedCategory=17