This dataset provides bias-corrected, dynamically downscaled temperature (°C) and precipitation (mm) projections for the seven subbasins of the Sakarya Basin, derived from the CMIP5 global climate models MIROC5 and CCSM4. The projections were downscaled to 18-km spatial resolution using the Weather Research and Forecasting (WRF) model, which was specifically calibrated for the hydroclimatic characteristics of the Sakarya Basin. The dataset includes monthly temperature and precipitation time series for three future windows—2020–2030, 2055–2065, and 2090–2100—corresponding to near-, mid-, and late-century conditions. A total of 14 bias-corrected CSV files are provided, representing separate projections for each subbasin and each climate variable. The projections cover seven hydrologically distinct subbasins of the Sakarya Basin, identified using the following abbreviations: ASAK – Lower Sakarya,GOK – Goksu,OSAK – Middle Sakarya,KIR – Kirmir,ANK – Ankara,POR – Porsuk,YSAK – Upper Sakarya.These data products are suitable for hydrological modeling, climate risk assessments, and interdisciplinary analyses such as WEFE nexus evaluations, and are formatted to support reproducibility and transparent scientific use.