Spatiotemporal Variability and Trends in Rainfall and Temperature and their Implications on Rain-fed Crop Production in the Northeastern Highlands of Ethiopia

Abstract Climate change and variability have received significant global attention due to their far-reaching impacts. The semi-arid regions of northeastern Ethiopia are among the epicenters of these climatic shifts. Hence, the study evaluates the spatiotemporal variability and trends in rainfall and temperature (1988–2020) and their impacts for rain-fed crop production across the Northeastern Ethiopian Highlands. This study used a 4 × 4 km gridded daily rainfall and temperature data obtained from the National Meteorological Agency of Ethiopia. Coefficient of variation, precipitation concentration index, and rainfall anomaly index were analyzed to test variability, while the Mann-Kendall test and Sen’s slope estimator were employed to detect trends and their magnitude, respectively. Pronounced spatial and seasonal variability in rainfall and temperature was observed, with highlands receiving more rainfall and experiencing lower temperatures than the lowlands. Rainfall also exhibited considerable spatial and seasonal variability, with the highest interannual variability recorded in the small and dry seasons. Rainfall anomalies demonstrated significant spatiotemporal heterogeneity, with below-average rainfall observed in 55%, 64%, 61%, and 63% of the years for the annual, main rainy, small rainy, and dry season, respectively. The precipitation concentration index showed moderate to high irregularity in rainfall distribution, with an increasing trend in rainfall irregularity. The Mann-Kendall test result on rainfall revealed a decreasing trend at most stations for annual, main season, and small rainy season rainfall over the study period, while the dry season rainfall exhibited a nonsignificant decreasing trend. All stations showed warming trends across seasons, but the magnitude was highest for maximum temperature. Correlation and linear regression analysis showed that rainfall and temperature fluctuations affected crop yields both positively and negatively. However, the impacts depend on the type of crop and location. Thus, tailored local adaptation strategies and context-specific planning could be essential for developing climate-resilient agriculture in the study region.