Check out this study from the Johns Hopkins Institute for Applied Economics, Global Health, and Study of Business Enterprise by two economists explaining the technical reasons we can say that Venezuela has entered a state of hyperinflation. They define is not only as 50% inflation per month, but persisting for at least 30 days, and the estimates had to be replicable. There are only 56 such instances recorded.
Venezuela reached this state nine days ago (December 3, 2016).
The lack of official data makes it trickier for Venezuela. Indeed, what mismanaged government wants to make it easier to say there is hyperinflation?
It is a technical paper, yet the conclusion is suddenly brief and accessible:
Venezuela, welcome to the record books. You have now entered the inglorious sphere of hyperinflation. It is a world of economic chaos, wrenching poverty, and death. Its purveyors should be incarcerated, and the keys should be thrown away.