Extremely cold weather, used by people of Sunderland and possibly Newcastle (I am not saying the 2 are the same, don't worry) as they are the only type of people who I have heard say it. "Brass monkey weather" is called thus because the temperature is so cold that "it would freeze the bollocks of a brass money".
#1: Boooar, its brass monkey weather!
#2: Ha? What?
#1: It would freeze the bollocks of a brass monkey
#2: Genius.
#2: Ha? What?
#1: It would freeze the bollocks of a brass monkey
#2: Genius.
by who knows but I May 27, 2006