The study utilised LSMS-ISA 2014 survey data for Niger, providing information on the sowing and resowing dates, along with department-level location data. Satellite-based rain estimation products, such as TAMSAT (Maidment et al., 2017), CHIRPS (Funk et al., 2015), and PrISM (Pellarin et al., 2022), were employed to derive rainfall onset indices such as the first wet day after April 15th of a 3day wet spell receiving at least x mm of rain (referred to as FWO) (Marteau et al, 2011). Along with climate data derived from Copernicus ERA5 models, spatial onset date simulations were performed with the SARRA-Py crop simulation model (doi:10.5281/zenodo.10125716) to compute water balance in the topsoil layer. A statistical analysis was conducted to investigate the correlation between the rainfall onset date map aggregated at departmental levels, and the mean successful sowing date per department from the survey.