Latitude is supposed to control climate. You learn this early. Move north, temperatures drop. Seems logical enough until you actually compare cities across the North Atlantic.
Take Happy Valley-Goose Bay in Newfoundland and Dublin. Both sit at 53°N latitude, so they’re getting identical winter sunlight. But January temperatures? Happy Valley-Goose Bay averages -22°C. Dublin barely freezes at 2°C. That’s a 24-degree gap between two places that should theoretically have similar winters.
Latitude
North American City
Jan Temp
European City
Jan Temp
53°N
Happy Valley-Goose Bay, NL
-22°C (12°F)
Dublin, Ireland
2°C (36°F)
50°N
Sept-Îles, QC
-20°C (-4°F)
Plymouth, UK
4°C (39°F)
48°N
Rimouski, QC
-15°C (5°F)
Brest, France
4°C (39°F)
45°N
Bangor, ME
-13°C (9°F)
Bordeaux, France
4°C (39°F)
43°N
Concord, NH
-11°C (12°F)
Bilbao, Spain
5°C (41°F)
41°N
New York, NY
-3°C (27°F)
Porto, Portugal
6°C (43°F)
The numbers for other latitudes tell the same story. Quebec’s Sept-Îles freezes at -20°C while Plymouth sits at 4°C. Drop down to 48°N and Rimouski is at -15°C, Brest at 4°C. Even New York, the mildest of the North American cities here, only reaches -3°C. Porto is at 6°C.
All the European cities on the map above stay above freezing. All the North American ones are well below zero.
The Gulf Stream creates this gap. Caribbean water flows northeast and reaches Ireland, Britain, and France still warm enough to change their entire climate. Nothing comparable exists for North America. Arctic air moves south and there’s no warm ocean current moderating anything.
The Gulf Stream itself may be weakening based on climate data from the past few decades. These temperature patterns we map today might not be permanent.
