This phrase is often used when it's bloody cold.

The origin of this phrase stems from the early explorers when traveling at sea in the icey cold. A brass monkey was used to hold the cannon balls in a pyramid shape, when it became freezing cold the holder ( brass monkey)would contract and the cannon balls would fall off.
This morning I went outside to take the bins out front, it was that cold it would of froze the balls of a brass monkey .
by Shaggenshano July 12, 2017
Get the Froze the balls of a brass monkey mug.