Frost is a significant hazard to grape production in many parts of New Zealand. In theory any crop can be protected, but economic and practical aspects limit the methods that can be used. When developing a vineyard, three factors should be taken into consideration: “Location, Location, Location”. Characteristics of a site likely to be vulnerable to frost damage are presented. The report contains a model developed during the course of writing this review for evaluating the potential risk of a site. The model is based on predicted phenology of the vine and the probability of the frost at any stage of the season and can be used where long-term temperature records are available.