how do you calibrate a fahrenheit thermometer? With celsius it's hilariously trivial, if the thermometer says it's about 0 when you see water freeze, it's correct enough for everyday use.

You do the exact same but use 32 degrees instead of zero. I know celsius is cool and good but most people seem incapable of understanding how its just fucking marks on a line and any non-sciencey advantage is pretty much null.