Aircraft icing poses a catastrophic threat to aviation safety. This study conducts a comparative investigation of two typical severe icing events, occurring in summer (July 2023) and winter (January 2024) over the Sichuan-Chongqing region, using pilot reports, ERA5 reanalysis data, geostationary satellite observations (Himawari-9/FY-4A), radar products, and sounding data. The research aims to disentangle the fundamental differences in large-scale circulation patterns, dynamic-thermal conditions,