To quantify the impacts of climate change on agricultural systems and to support policy processes and farm level decisions, the agricultural meteorology community is extensively applying climate-crop modelling approaches. The herein study evaluates the impact of two climate change scenarios (Representative Concentration Pathways-RCPs 4.5 and 8.5) on main crops (millet, sorghum and cowpea) grown in two agroclimatological regions (Soudano-Sahelian and Sahel) in the Republic of Niger. Climate projections using HadGEM2-ES model show increasing precipitation trends of up to + 30 % under RCP 8.5 in Birni N ' Konni (Soudano-Sahelian) and a decrease of 1 % under RCP 4.5 in Mare de Tabalak (Sahel) when comparing the 2021-30 and 2071-80 periods. The number of dry days and heavy rainfall events during the wet-season are also expected to gain in frequency over the century. As a result, the productivity of major crops is threatened, with potential dire consequences for national food security and the income of millions. The emerging findings of the crop-modelling work using AquaCrop show a decrease/increase yield trends for millet, sorghum and cowpea of about 0 to -50 %, + 5 to -20 %, + 11 to + 18 %, respectively, by the end of the century (2060-80), depending on the agroclimatic zone, sowing date and RCP. Overall, the emerging findings of this work can be used to inform agricultural trans-formation and adaptation to climate change by promoting a higher resilience against both excess of water (due to high rainfall events) and lack of water resources (due to extended dry periods).