The temperate fruit tree climate overcomes the dormancy stage by exposure to low temperatures. The lack of winter chill affects sweet cherry quality and yields of cherry crops. The time which these plants should remain under low temperatures is denominated chilling requirement. This is essential to obtain a normal leafing and blooming. This study used the chill unit (CUUM) method calculated by Utah model modify by Fruit & Nut Research Information Center, UC Davis. This study was carried out on two cherry producer counties, Luján de Cuyo and Tupungato of Mendoza Province, Argentine. Those areas have experimented significant yields reduction each time the chilling offer was not enough. Because of this specie have specific physiologic requirement and these areas have great annual temperatures variability, it is necessary to study its climatic profile in reference to winter chilling. Luján de Cuyo County had a mean of 1.106 CUUM, enough for varieties with low and intermediate requirements. Ninety percent of winters fluctuated between 824 and 1.388 CUUM. Consequently some years the chilling availability could be enough only for low chill requirements varieties. Tupungato has a mean of 1.445 CUUM, indicating that it was enough for high requirements varieties. However ninety percent of winters, CU oscillated between 1.152 y 1.738 CUUM indicating there was years that winter chilling was enough for intermediate requirements varieties. The estimated probability to attain 1.400 CUUM, at Luján de Cuyo County was 18%, while at Tupungato County was 66%. These studies establish the bases to develop a varietal zonation based on an important limitation of sweet cherry, improving its productivity and development.