Why Europe is further north than it feels

Ask people whether Paris or Montreal is further north and most pick Montreal. It has snowy winters that run into April, while snow rarely settles in Paris. Yet Paris sits at 48.9° north and Montreal at 45.5°: Paris is about 380 km closer to the North Pole. It is one of the most common mistakes in Latitude Line, and it isn't a one-off.

Pairs that surprise people

Each European city here is level with, or north of, a North American city that feels much colder.

It works south of the equator too. Sydney (33.9° S), Cape Town (33.9° S), Santiago (33.4° S) and Buenos Aires (34.6° S) sit within about a degree of each other, though few people would group them.

Why the weather fools us

We tend to judge how far north a place is by its weather, and western Europe has unusually mild winters for its latitude. Two things do most of the work. At these latitudes the prevailing winds blow from the west, so Europe's air arrives off the Atlantic, which holds on to summer heat far longer than land does. Eastern North America gets its winter air from the frozen interior of the continent instead. On top of that, the North Atlantic Current, the far end of the Gulf Stream system, carries warm water towards north-west Europe; it is part of why Norway keeps ice-free ports inside the Arctic Circle.

Climate scientists still argue over how much of the difference each one explains, but the pattern is clear: at the same latitude, the west side of a continent is far milder in winter than the east. That is why Vancouver feels so much gentler than Newfoundland, and why Europe as a whole feels further south than it is.

Anchor cities

The reliable fix is to stop reading the weather and learn a handful of reference points. Then, in the game, place each city against the nearest anchor.

• About 60° N: Oslo, Helsinki and St Petersburg, with Anchorage a little further north (61.2°).
• About 50° N: Frankfurt, Prague, Kraków, Kyiv and Winnipeg, with Vancouver just south (49.3°).
• About 40° N: Madrid, Naples, Istanbul (41.0°), Beijing, Denver and New York.
• About 30° N: Cairo, New Orleans and Shanghai (31.2°), with Delhi a little south (28.6°).
• On the equator: Quito and Kampala, with Singapore 1.3° north and Nairobi 1.3° south.

East and west have surprises too

The same trap exists for longitude, which is what Longitude tests. Reno, Nevada, is further west than Los Angeles. Ships crossing the Panama Canal from the Atlantic to the Pacific come out further east than they started, because the canal runs from north-west to south-east. Drive south from downtown Detroit and you reach Canada: Windsor, Ontario, sits just south of it across the river. And Madrid is further west than London, yet Spain keeps Central European Time, an hour ahead of the UK.