cold enough to freeze the balls off a brass monkey

rude Extremely cold, usually said of the weather. Though often believed to refer to so-called "brass monkeys" of a naval ship (brass trays where cannonballs were supposedly stored), this has been widely discredited as anachronistic; it is more likely a semi-vulgar reference to bronze replicas of the Three Wise Monkeys (i.e., "Hear no evil, see no evil, speak no evil") often sold as popular tourist souvenirs in China and Japan. I wouldn't want to be trapped out in this weather tonight, it's cold enough to freeze the balls off a brass monkey!