Protea ‘Pink Ice’ cut flowers are one of the most popular products worldwide in the Protea genus. Small and medium Chilean growers appreciate this cultivar because it is easy to cultivate, rustic, has high yields, and flower stems are formed year-round. Unfortunately, in Chile there is no information about the time of development of the inflorescence of Protea ‘Pink Ice’ according to each season. The aim of this study was to determine the base temperature for the development of flower buds of Protea ‘Pink Ice’, from 1 cm diameter stage until harvest, and growing degree days (GDH) for different seasons in a field located in Maule Region. Groups of flower buds were selected on 4 different dates during a chronological year and followed until harvest stage, measuring bud diameter and length. Temperature was recorded every 15 or 30 min. The results show that the flower buds labeled in September reached a higher diameter compared to those labeled in April, and those buds marked in September or December were longer. On the other hand, results pointed out that, for the coastal area of Maule Region, the base temperature was around 1°C. The flower buds took 150-202 days from bud 1 cm diameter to harvest time, and around 46,000-50,000 GDH. It is concluded that it is possible to predict the approximate harvest date of the inflorescence of Protea ‘Pink Ice’ based on the thermal sum in GDH with using 1°C as the base temperature.