Arizona has not legalized marijuana. Possession of any amount of marijuana is still a crime and will likely lead to jail time. They have a medical marijuana program which started in 2010 and currently has over 60,000 patients. You need a card which is issued by doctor to be a part of the program. There are a number of qualifying medical conditions that make one eligible for the program.
Recreational marijuana is not currently legal in Arizona, but is on the ballet for 2016. Proposition 203 narrowly passed in Arizona in 2010 allowing medical marijuana to be sold in Arizona. Dispensaries opened up for the first day of sales on December 6th 2012. There was around 77 dispensaries opened up in the first year of business for medical marijuana in Arizona.
Arizona has voted for the legalization of medical marijuana by a vote of 50.13, barely making a majority. Proposition actually failed many times before it was finally voted for. Arizona very first dispensary opened in April of the year 2013. In the current year 2016, there are many dispensaries in the state.
We will know the results of the Arizona Marijuana Legalization Initiative after the November 8th election, and if it passes, recreational cannabis will be legal for adults over the age of 21. Hopefully it passes!