no cool, n. — Green’s Dictionary of Slang

no cool n.

[joc. use of sl. + ref. to the status of that part of the state]

(US campus) northern California.

1989		P. Munro Sl. U.
1997		K. Kainulainen ‘University Euphemisms in Calif. Today’ 🌐 Besides the geographic ‘So Cool’ meaning ‘Southern California’ and ‘No Cool’ meaning ‘Northern California’ there is a great number of euphemistic expressions which are about the ‘in’ things in California.