Almond (Prunus amygdalus Batsch) blooming date is mainly determined by the temperatures during the dormancy period, from the onset of the winter rest to just before blooming. In this work we have developed a model to estimate the end of the winter rest in almond based on the relation between the date of full bloom and the previous temperatures during several years. The chilling requirements to cover the winter rest and the heat requirements to reach full bloom were estimated for a group of 47 cultivars covering all the blooming period of almond. It was found that most cultivars have chilling requirements between 400 and 600 CU, whereas the span of heat requirements was wider, from 5,500 to 9,300 GDHºC. Some cultivars have high chilling requirements and low heat requirements whereas others have opposite requirements, showing that these differences can affect their adaptability to different climatic conditions and be used in breeding programs to obtain new cultivars with higher and lower temperature requirements for blooming.