In this study, the phenological characteristics of some apple varieties grown in the Kalecik district of Ankara province, the number of days between effective heat summation requirements, and phenological phases were determined. The research was conducted on Royal Gala, Granny Smith, Jersey Mac, Spur Golden and Red Chief apple varieties. The threshold temperature of +10°C was accepted as the temperature value for the determination of the heat summation requirements of the varieties. The effective heat summation above +10°C during the growing season of varieties was determined as 819.1-1986.3°C days in 2015 and 865.1-2031.2°C days in 2016. The number of days from full bloom to harvest was 85-75 days in 2015 and 132-219 days in 2016.