Understanding aridity patterns and their evolution under future climate conditions is essential for sustainable environmental planning in semi-arid regions. This study investigates the spatiotemporal variability and projected changes in aridity across western Iraq, using historical data (1993-2023) and future climate projections (2020-2100) from five meteorological stations strategically located across a semi-arid region. A comprehensive suite of aridity and drought indices was employed, including the Reconnaissance Drought Index (RDI), the United Nations Environment Programme (UNEP) Aridity Index, De Martonne and Lang classifications, Standardized Precipitation Index (SPI), and Potential Evapotranspiration (PET). Future climate variables were downscaled using Long Ashton Research Station Weather Generator (LARS-WG 8) weather generator, driven by four Coupled Model Intercomparison Project Phase 6 (CMIP6) models (ACCESS-ESM1-5, HadGEM3-GC31-LL, MPI-ESM1-2-LR, MRI-ESM2-0) under two Shared Socioeconomic Pathway ( SSP245 and SSP585) emission scenarios. Results indicate that western Iraq exhibits a predominantly arid to hyper-arid climate, with spatial heterogeneity influenced by latitude and proximity to water bodies. The southern stations (Kerbala and Najaf) show the highest aridity levels, which are projected to intensify significantly, particularly under the SSP5-8.5 scenario, where PET is expected to increase by up to 12% by 2100. These findings underscore the increasing climatic stress on water resources and agriculture and provide critical inputs for climate-resilient policy and adaptation strategies in arid and semi-arid zones.