Large-ensemble 21st century monthly hydro-climatological forcing dataset for the PARIS 1.5C (P1p5C) scenario. The P1p5C scenario extends from the Paris Agreement’s NDCs and aligns with its long-term goals for aiming to limit and stabilize human-induced global climate warming to 1.5°C by the end of this century. The dataset consists of a 900-member ensemble, which is constructed by spatially disaggregating a 50-member ensemble of the MIT IGSM zonal climate projections based on hydroclimate change patterns from the 18 CMIP6 climate models. The dataset contains nine key meteorological variables on a monthly scale from 2021 to 2100 at a spatial resolution of 0.5°x 0.5°, including precipitation, air temperature (mean, minimum and maximum), near-surface wind speed, shortwave and longwave radiation, specific humidity, and relative humidity. The abbreviations of the variables are listed as below: precipitation (Prep), air temperature (mean (Tair), minimum (Tmin) and maximum (Tmax)), near-surface wind speed (WIND), shortwave (FSDS) and longwave (FLDS) radiation, specific humidity (Huss), and relative humidity (Hurs).