^If you're an American and you've ever had a conversation with someone from another country about the weather, you've probably been a little confused when he or she says that the afternoon
temperature is a nice 21 degrees. To you, that might sound like a chilly winter day, but to them, it's a pleasantly warm springtime temperature.
That's because virtually every other country in the rest of the world uses the
Celsius temperature scale, part of the metric system, which denotes the temperature at which water freezes as 0 degrees, and the temperature at which it boils as 100 degrees. But the U.S. and a few other holdouts – the
Cayman Islands,
the Bahamas,
Belize and
Palau – cling to the Fahrenheit scale, in which water freezes at 32 degrees and boils at 212 degrees. That means that the 21 degrees C temperature that we previously mentioned is the equivalent of a balmy 70 degrees F in the U.S.
The persistence of Fahrenheit is one of those puzzling American idiosyncrasies, the equivalent of how the U.S. uses the word soccer to describe what the rest of the planet calls football. So why is it that the U.S. uses a different temperature scale, and why doesn't it switch to be consistent with the rest of the world? There doesn't seem to be a logical answer, except perhaps inertia. Americans generally loathe the metric system – this
2015 poll found that just 21 percent of the public favored converting to
metric measures, while 64 percent were opposed.