This article was originally posted on David Taylor's data visualisation blog Prooffreader.com in November 2013. David very kindly agreed to let us repost it here, which is pretty lovely of him.

Canada is farther north than the United States: everybody knows this, and for the most part it's true.

But an article in Monitor on Psychology says people tend to take these geographical mental shortcuts too far: most Americans are surprised to find that all of Florida is farther south than the Mexican border, for example.

So let's see how much of the United States is below Canada's most southerly city, Windsor, Ontario (I won't cheat and count the little islands in Lake Erie that belong to Canada):



For the record, the red area comprises 22 per cent of the surface area of the contiguous United States (38 per cent if you include Alaska), and 15 per cent of its population. Windsor is just 25 km further north than the California-Oregon border.

The paper also states that both Americans and Canadians tend to imagine Europe to be more southerly than it is in relation to them: they equating Spain's latitude with the southern states, for example. Let's have a look, without that pesky Atlantic Ocean in the way:



Once again using the online tool Mapfrappe, I've marked the Latitudes of Windsor and of the 60th parallel, which divides the Prairie provinces from Northern Canada.

You'll notice Windsor, which has some cold winters, is even with northern Spain, which decidedly doesn't. That's another mental shortcut we all share: north = cold. But it's not that simple when you have a nice Gulf Stream warming your coastline, as Europe does.

The geographical comparison was less surprising to me than the demographic one. In 2013, I posted a blog about Canadian population by latitude, whose data was a little coarse because Canada Post and Statistics Canada have copyrighted the most finely detailed geographical boundaries used in the census.

But a wonderful reader pointed me to the ISLCP II Project, which lists the population of the entire planet for every quarter-degree of latitude and longitude (albeit from 1995, but I'll take it). Have a look at the relative populations by latitude of the United States, Canada and Europe:

The most northerly Canadian city with a population of over 500,000 is Edmonton, Alberta: it's at about the same latitude as Dublin, Manchester and Hamburg. Around 15 per cent of Europeans live farther north than this. (The demarcation of Europe and Asia is fuzzily defined; I chose it as including Istanbul and Moscow, which is north of Edmonton.)

In fact, the median latitude of population in Europe is nearly 4 degrees higher than in Canada – that's around 400km.

Thanks to these histograms I realized I'm as susceptible to that misfiring geography heurism as anyone: in my mind, Hawaii was about the same latitude as Sacramento, California. But it's over 500km farther south than the mainland United States.

David Taylor is a Montreal-based writer, who runs the data visualisation blog Prooffreader.com.

Editor's note: the calculation that the median Canadian lives at between 45 and 46 degrees latitude, roughly on a par with Milan, is CityMetric's own. If we've screwed up, it's our error, not David's.