Now once upon a time, I was told that the scale had something to do with the melting point of butter, which I think is meant to be 100 degrees Fahrenheit. But then what determines 0 degrees Fahrenheit, leading to the awkward 32 and 212 degrees for water freezing and boiling? I have no answer.
Well, according to Wikipedia, nobody really knows where the scale comes from! There are a number of theories. Here's one unlikely but charming explanation:
[A] not so well-known version of the origin of the Fahrenheit scale depends on Fahrenheit himself being a Freemason (of which there is no definitive evidence). In Freemasonry, there are 32 degrees of enlightenment, 32 being the highest. The use of the “degree” as well is said to have been derived from the degrees of masonry. This may well be coincidence, but there is no conclusive evidence to the contrary, so the thought persists.Wow! The Freemasons really do control everything!