Advancing Spatiotemporal Analysis of Climate Variability: Current Trends, Future Projections, Causes, and Impacts on Maize Production in Southern Ethiopia

This study provides a comprehensive assessment of climate characteristics, variability, and their impacts on maize production in Southern Ethiopia, integrating historical observations with future climate projections. Using advanced statistical analyses, including Mann-Kendall trend tests and Rotated Empirical Orthogonal Functions (REOF), we identify significant warming trends in both minimum and maximum temperatures across all seasons, alongside spatially heterogeneous rainfall variability strongly influenced by ocean-atmosphere interactions such as ENSO and the Indian Ocean Dipole. Our analysis reveals that maize yields in key agricultural zones, Sidama, South Omo, and Wolayita are highly sensitive to seasonal rainfall and temperature fluctuations, particularly during critical phenological stages. Future climate projections under SSP1 and SSP5 scenarios indicate decreasing rainfall during the main maize growing season (MAM) coupled with rising temperatures, exacerbating water stress and threatening crop productivity. Conversely, increased rainfall during the short rains (SON) may offer opportunities but also pose risks from waterlogging and pest outbreaks. These findings underscore the urgent need for climate-smart agricultural strategies, including drought-resistant varieties, adjusted planting calendars, and enhanced water management, to safeguard food security and rural livelihoods amid evolving climate risks in Southern Ethiopia. This is designed as a logical progression from foundational context to applied agricultural implications. An integrated climate–agriculture assessment for South Ethiopia, synthesizing long-term observations, advanced statistical diagnostics, and state-of-the-art climate model projections to unravel past trends, key variability drivers, and future risks. The first section (Fig. 1) maps the region’s geographic setting, elevation, soils, and agroecological zones; factors that dictate crop suitability and shape vulnerability to climate extremes. Baseline climatologies of rainfall (Fig. 2) and minimum/maximum temperature (Fig. 3, supported by Fig. 3a) capture seasonal cycles and spatial gradients, forming essential references for detecting anomalies. Trend analyses (Fig. 4–5, supported by Fig. 4a, 5a–5d) uncover significant spatial–temporal changes in rainfall, temperature, and sea surface temperature (SST) between 1981–2024, including season-specific precipitation declines or increases and pervasive warming in both minimum and maximum temperatures. These shifts have direct implications for heat stress, evapotranspiration rates, and the potential redefinition of agroecological zones. Rotated Empirical Orthogonal Function (REOF) analysis (Fig. 6 and 8, supported by Fig. 8a–8c) isolates dominant rainfall variability modes, linked to large-scale ocean–atmosphere phenomena. Correlation and composite diagnostics (Fig. 7, supported by Fig. 7a–7c) emphasize the seasonal influence of SST anomalies, El Niño-Southern Oscillation (ENSO), and the Indian Ocean Dipole (IOD), clarifying connection pathways that govern rainfall variability. The climate–agriculture coupling (Fig. 9) demonstrates measurable impacts of seasonal rainfall anomalies on maize yield, production, and harvested area, highlighting farmers’ adaptive strategies under water stress. Multi-model ensemble analyses (Fig. 10–11; see also supplementary Figs. 10a–10c, 11a–11c) under two Shared Socioeconomic Pathways: SSP1 (Sustainability) and SSP5 (Fossil-Fueled Development), elucidate model uncertainties and indicate projected shifts in rainfall regimes and enhanced warming, thereby informing targeted adaptation strategies. Collectively, these findings advance scientific understanding of climate–agriculture interactions, enhance seasonal forecasting capability, and provide evidence-based guidance for policymakers, extension services, and climate-resilient agricultural investment in one of East Africa’s most climate-sensitive regions. Distinct seasonal and spatial climate variability in Southern Ethiopia strongly influences maize production dynamics. Rainfall variability is closely linked to global ocean-atmosphere drivers such as ENSO, Indian Ocean Dipole, and Atlantic SST anomalies. Maize yields are highly sensitive to seasonal rainfall and temperature changes, with critical growth stages most vulnerable to climate fluctuations. Future projections indicate reduced rainfall during the main growing season (MAM) and increased temperatures, posing significant risks to maize productivity. Adaptation strategies including drought-resistant crops, adjusted planting schedules, and improved water management are essential to enhance resilience and food security.