High resolution (0.11°) regional climate simulations were carried out by the researchers at Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research, Atmospheric Environmental Research (KIT/IMK-IFU) as part of the West Africa Science Service Center on Climate Change and Adapted Land Use (WASCAL) Project. One of the goals of the WASCAL project is to provide the best accuracy in regional climate simulations over the entire West Africa region for a large proportion of the 21st century. The regional climate model employed in the project was the COSMO-CLM (COnsortium for Small-scale MOdelling in CLimate Model) 
version 4.8_clm19 forced by one global circulation model (GCM), the Max Planck Institute Earth System Model (MPI-ESM-LR, Stevens et al. 2013) under the Representative Concentrative Pathways 4.5 (RCP 4.5). Further control runs with ERA-Interim reanalysis products (Dee et al. 2011) were also used for model verification. Therefore, daily outputs of near-surface relative humidity, obtained from the hourly simulations of CCLMv4.8.19, driven by ERA-Interim reanalysis, are hereby presented.