Chilling hours are the number of hours between November and February with temperatures between 0 and 7 °C. Each fruit species has a minimum requirement: 500–1,000 h for peach, 800–1,200 h for cherry, 200–500 h for almond.
Climate change impact
Global warming is reducing accumulated chilling hours in many fruit-producing regions, especially in southern Spain. This causes irregular budding, poor flowering, and crop losses. Farmers must seek varieties with lower chilling requirements or apply products to compensate for lack of natural cold.