Observed and CMIP6 projected rainfall variability and change in drylands of southern Ethiopia

Rainfall variability and change are critical drivers of food production in tropical regions. This study analyzed rainfall trends and variability in the drylands of Wolaita Zone (DLWZ), southern Ethiopia. It used observed rainfall data (1990–2022) and projections for 2026–2075 under two shared socioeconomic pathways (SSP2-4.5 and SSP5-8.5). Rainfall variability was assessed using the coefficient of variation, while trends were examined with the modified Mann–Kendall test and Sen’s slope. Results show extremely high (>30%) to high (20–30%) seasonal and inter-annual variability during 1990–2022, with decreasing rainfall trends except for winter, which showed a non-significant increase. Projections indicate medium (10–20%) to high variability in annual rainfall and high to extremely high variability in seasonal rainfall. Significant decreases are expected in spring rainfall, while summer and winter rainfall are projected to increase, particularly in 2051–2075. These findings suggest that persistent variability and declining rainfall during critical seasons may intensify risks to agricultural production in southern Ethiopia. The dataset provides a valuable basis for future studies on the impacts of rainfall change on crop and livestock systems.