cold enough to freeze the balls off a brass monkey

The phrase "cold enough to freeze the balls off a brass monkey" is an idiom used to describe extremely cold weather conditions. It implies that the temperature is so frigid that it could cause the metallic testicles of a brass sculpture or ornament, known as a "brass monkey," to freeze and possibly fall off due to contraction. However, it's worth noting that this phrase is often used figuratively rather than referencing any actual objects.