Imperial, because of it's vagueness people use other measurements as well.
Something is x stories high.
Something is a "stones throw away".
Though i do appreciate Fahrenheit for how it scales with humans. 0 is really damn cold, 100 is really damn hot, while in Celcius 0 is kinda chilly and 100 is instant death.
It's actually supposed to be the body temperature. Due to imprecise measurements, it's actually having a light fever. Flip note: C scales the same - 0 is the water freezing point, and then you have the same scaling as F but in 5s instead of 10s. [and you gotta remember: (f-2pow5)*5/9].
That's an old debate, yet if you are born/used to C, F is pretty horrific.