The blossoming of almond trees often coincides with spring frosts, significantly increasing the risk of reducing or even nullifying yield. However, there is genetic variability in their response to very low temperatures and frost. Therefore, identifying resistant cultivars and genotypes through reliable evaluation methods and utilizing their genetic potential is an effective strategy to overcome spring frost damage. Accordingly, this study investigated the response of different almond cultivars/genotypes to frost damage using controlled freezing and thermal analysis. For this purpose, two experiments were conducted separately in 2019 and 2020. The first experiment adopted thermal analysis to assess the spring frost tolerance of six almond genotypes (S1, S2, A5, A8, A11, and A23) at three phenological stages (green tip, popcorn, and open flower). The second experiment used thermal analysis, visual inspection, and ion leakage to examine the spring frost tolerance of 26 cultivars/genotypes in 2019 and 30 in 2020 at the open flower stage under a controlled temperature chamber. The research findings demonstrated that the phenological stage and cultivars/genotypes significantly influenced the exotherm temperature of the almond flower buds. The positive correlation between the exotherm temperature of the flower and leaf buds, frost damage, and ion leakage indicated that thermal analysis could be a practical tool for assessing frost tolerance in almonds. Based on the thermal analysis, the cultivars/genotypes D12, Saba, KD101, KD99, A5, and C16 have been identified as top candidates for future almond breeding programs.