Today’s so cold it could freeze the balls off a brass monkey! means it’s very, very cold. This expression is commonly used in most English-speaking countries even though it sounds very vulgar [not polite – “balls” is slang for kin-tamma in English].
It’s generally believed that a brass monkey is actually a kind of tray that used to be used on old sailing ships to hold cannon balls in place. I once gave a presentation on student radio (2SER) explaining the details behind this belief. This morning when I decided to make the expression the focus of this Blog entry, I went to Wikipedia (an online encyclopaedia [a big book full of information on almost anything]) to check my facts – it turns out I’m completely wrong!
In the mid 1800’s, brass statues of monkeys were apparently [I’ve read/heard this but it may not be true] common decorations in living rooms. Around this time, the expression It’s cold enough to freeze the tail off a brass monkey became popular. Some time after that, the vulgar-meaning “balls” was used to replace the word “tail.” The myth [a story that is not true] that its origin is from sailing ships has made this expression more acceptable than it probably should be!