Q : Is smoking weed (marijuana) legal in some States?

Answer: No. Every State, from Alabama, Colorado, Kentucky to Vermont, including Arizona and every State in between, has enacted various criminal penalties for the possession, use, cultivation, transportation and distribution, of marijuana, including even the smallest of quantities.

Arizona punishes possession of amounts less than two pounds as a class six felony with fines between $750 and $150,000 and jail or prison time from six months to a year and a half.

A few States have decriminalized marijuana use and possession in small amounts (N. Carolina and California for example) but even there, its still illegal.