This paper presents a new approach for simulating fatigue crack growth in floating offshore wind turbine (FOWT) blades subjected to extreme wind events, such as typhoons. By analyzing field wind speed data during Typhoon Haikui (2023), this study identifies notable deviations from the IEC-defined normal turbulence model (NTM) conditions. These deviations, resulting from non-Gaussian wind characteristics with elevated skewness and kurtosis, lead to more intense dynamic loading, causing localized stress concentrations and accelerating fatigue damage in key blade regions. The study explores the impact of these extreme wind conditions on crack growth at multiple critical blade locations through simulations involving various design load cases (DLCs). A multi-body FOWT simulator, coupled with finite element analysis, is utilized to model the crack propagation process. The findings demonstrate that extreme wind conditions significantly shorten the blade’s fatigue life, triggering earlier crack initiation and faster propagation. This research underscores the critical need for accurate wind field modeling, especially for non-Gaussian wind processes, to predict the structural performance and failure mechanisms of FOWT blades under real-world extreme conditions. These insights are instrumental in guiding the design and optimization of more durable FOWT blades, particularly in regions vulnerable to severe weather events.