Pistachio is one of the most important horticultural products and adapted to the arid and semi-arid climate of Iran. In recent years, global warming has not met the cooling demands of pistachio trees. Higher temperatures will eventually reduce yield, delays in flowering and low fruit set even in a productive year. Yazd province has a hot-arid regions climate and most of the pistachio trees grown in this area do may not be exposed to sufficient cooling. The purpose of this study was to achieve the chilling hours of commercial (Akbari, Ahmad Aghaei, Fandoghi) and native cultivars (Choruoki, Haj Abdollahi, Shasti) in the winter in Ardakan and Khatam. The results of this study showed that the cooling hours requirements calculated by the Utah positive model were higher than the cumulative model during the recession period of pistachio trees within the last ten years (2009-2019). Also, during the mentioned statistical period, the annual chilling requirement, cultivars such as Fandoghi was met almost in all years while cultivars such as Choruoki was never fully produced; so, this cultivar is not recommended for cultivation in the study area. For Ahmad Aghaei / Akbari cultivars, based on the positive Utah model, cooling requirements were obtained in the ten-year period, whereas due to the cumulative model, it was not observed. In addition, Akbari in Khatam city and Haj Abdollahir in Ardakan city are the most suitable cultivars in terms of physiological stages, cold storage and crop production.