Climate change is increasingly exacerbating the risk of desertification, particularly in semi-arid and transitional climate zones, through rising temperatures and increased atmospheric water demand. This study comparatively analyzes spatial and temporal changes in aridity conditions across T & uuml;rkiye for two climate normal periods (1958-1990 and 1991-2020) using high-resolution TerraClimate dataset and the De Martonne, UNEP, Erin & ccedil;, and Budyko Dryness indexes. Spatial validation analyses demonstrate strong agreement between TerraClimate-based indices and MGM station data (r = 0.82-0.84). Additional validation using ERA5-Land also supports the reliability of the Budyko (r = 0.78) and UNEP (r = 0.76) indices. Delta analyses reveal a consistent expansion of semi-arid areas by + 0.36% to + 0.87%. Furthermore, water-energy balance-based indices indicate that increasing potential evapotranspiration (PET) has become a more dominant driver of recent drying processes than precipitation variability. In conclusion, aridity change in T & uuml;rkiye is mainly concentrated in semi-arid transition zones and is increasingly driven by rising atmospheric water demand. The findings emphasize the importance of multi-index and water-energy balance approaches for basin-scale risk management and climate adaptation planning.