More frequent and widespread large fires are occurring in the western United States (US), leading to mounting detrimental effects on atmospheric quality, ecosystems, and human society. However, reliable methods for predicting these fires, particularly with extended lead times and a high spatial resolution, remain challenging. In this study, we focused on predicting large fires one month in advance with a spatial resolution of 1 km. We proposed an interpretable and hybrid machine learning (ML) model, that explicitly represented the controls of fuel flammability, fuel availability, and human suppression effects on fires. The model demonstrated notable accuracy with a F 1 -score of 0.846±0.012, surpassing process-driven fire danger indices and four commonly used ML models by up to 40% and 9%, respectively. More importantly, by demystifying the 'black box' of each ML model using the explainable AI (XAI) techniques, we identified substantial structural differences across ML fire prediction models. The relationships between fires and their drivers, identified by our model, were aligned closer with established fire physical principles. With this highly accurate and interpretable model, we revealed the strong compound effects from multiple climate variables on the dynamics of large fires, including megafires in the western US. Our findings highlight the importance of assessing the structural integrity of models in addition to their accuracy. They also underscore the critical need for trustworthy AI algorithms to address the challenges posed by the rise in compound climate extremes linked to large wildfires.