This study evaluates climate change impacts in the Yarmouk River Basin (YRB) using the Statistical Downscaling Model (SDSM) and observed data from six stations (1989–2017). The second-generation Canadian Earth System Model (CanESM2) was applied under Representative Concentration Pathways (RCPs) scenarios for 2018–2100, demonstrating high accuracy in modeling the arid climate (R²: 0.87–0.996 for calibration; 0.799–0.998 for validation).

Projections show temperature increases of up to 1.8°C and precipitation declines of up to 49% by 2100, with greater maximum temperature rises in the east, higher minimum temperature increases in the west, and severe precipitation reductions in the agriculturally vital western region. Extreme climate events, including more heatwaves, fewer cold spells, and prolonged dry periods, suggest growing climate instability.

The evaluation of current climate conditions reveals sharper temperature increases and precipitation declines than RCP8.5 projections, highlighting an elevated risk of drought and water scarcity. These findings underscore the model's utility in assessing climate impacts and emphasize the need for targeted adaptation strategies, offering insights relevant to other arid and semi-arid regions globally.