Two-fifth of the world's population will be confronted by dire land and water shortage for food production by 2050. Here we provide nuanced insights into the Sahel dryland dynamics and rationale behind its underperforming croplands amid climate extremes. We develop a gridded multi-criteria drought index and analyze its spatial and temporal degree of uniformity to designate the drought, climate and cultivable zones. Evidence is drawn from Sahelian Sudan, representing 1.03 million km2 of the African Sahel, during 1940–2020. Cultivation of marginal lands has persisted apace. The peak areas of these marginal lands explain ~50 % of the variations in crop yield, considering the two staple crops, sorghum and millet. Accordingly, the low yields mismatch the steadily growing planted areas of these crops. Droughts expand (shrink) the median size of hyper-arid (arid) area by 466 % (46 %) compared to wet conditions, limiting farming opportunities for 3.5–35.8 % of the croplands. The northernmost borderline of the arid zone determines the rainfed suitability, but potentially cultivable arid areas require contingency risk-reduction plans. Conversely, semi-arid and dry sub-humid zones reveal areas endowed with uniform climate. Skillful climate forecasting should thus guide policymaking towards sustainable agriculture therein. The paper suggests paths towards more effective agricultural policy interventions. Agricultural production entails the Sahel drought being defined in terms of agricultural impacts instead of meteorological conditions. Land use planners and inhabitants must relieve this plight of misconceiving and overlooking the fact of intrinsic interannual rainfall variability. Determining what a dangerous drought is crucial for the Sahel agriculture sector or system. Sahel farming systems should opt for highly flexible agricultural practices based on the above-identified cultivable areas.