Climate change affects rainfall seasonality and timing in maize-based agroecological zones of Ethiopia

Rainfed subsistence agriculture is vital for food security in East Africa, particularly in regions where maize is the dominant crop. Its success depends heavily on rainfall patterns, making it vulnerable to climate variability and change. This study analyzes the variability in Rainfall Onset Date (ROD), Rainfall Cessation Date (RCD), and Growing Season Length (GSL) across major maize-growing agroecological zones (AEZs) in Ethiopia. It also examines the potential impacts of future climate scenarios and identifies adaptation strategies to reduce risks to maize production. High-resolution historical data (1981–2019) and projections from CMIP6 models under the SSP5-8.5 scenario (2020–2049) were used. The results show significant variation in ROD, RCD, and GSL between AEZs and climate periods. Future projections indicate delayed ROD (by 10 to 49 days), earlier RCD (by 6 to 95 days), and a shorter GSL (by 10 to 71 days), with high interannual variability. These shifts may expose maize crops to water stress during critical growth stages, increasing drought vulnerability and reducing yields. To sustain production, agricultural practices must be reevaluated. Recommended adaptation strategies include adjusting planting dates, adopting drought-tolerant and early-maturing maize varieties, and improving irrigation efficiency. Revising cropping calendars and promoting collaboration among policymakers, researchers, and farming communities are essential to developing effective, site-specific responses. These efforts are critical to strengthening the resilience of maize-based farming systems and ensuring food security under changing climatic conditions in Ethiopia and the wider East African region.