another way of saying its a little chilly

A phrase used to describe a chilly, brisk temperature; cold enough to cause your nipples to harden if you are without a jacket or overcoat.

All of midwestern America during the winter, especially Minnesota.

A word-play on the term nippy to describe cold weather and simultaneously include boobs nonchalantly in the conversation. Often followed by some form of "the breast of weather" to keep the joke going.