Climate trends, variability, and changes in extreme indices under future projections over Central Oromia, Ethiopia

Ethiopia is highly vulnerable to extreme weather and climate events, making regional and local projections essential for impact monitoring and adaptation planning. This study analyzes climate trends, variability, and extreme indices in the wheat-growing areas of Central Oromia using daily rainfall and temperature data (1991–2022) from the Ethiopian Meteorological Institute, along with CMIP6 projections under SSP4.5 and SSP8.5 for the 2050s and 2080s. Statistical analysis using various packages, including the Mann–Kendall test, revealed statistically significant increasing trends in annual rainfall at most stations especially during the Kiremt and Belg seasons under both scenarios. Maximum and minimum temperatures also showed significant upward trends, with higher increases under SSP8.5. Rainfall projections indicate moderate to high concentration (11.30–58.19%) and irregular distribution, with growing seasons starting 1–23 days earlier, ending 23–36 days later, and lasting 17–54 days longer. Mean annual precipitation is projected to rise by 2.99–75% (2050s) and 0.67–85.77% (2080s), though some areas may see declines of 3.87–17.42% and 4.64–14.92%, particularly under SSP8.5. Maximum and minimum temperatures are expected to increase by 0.37–5.72 °C and 1.87–6.35 °C, respectively, compared to the baseline, with minimum temperatures rising more than maximum temperatures across all scenarios. Extreme temperature indices show substantial increases in both hot and cold extremes, especially under SSP8.5, while changes in precipitation extremes vary by location. These localized projections for Central Oromia offer critical insights to support targeted adaptation strategies for farmers, policymakers, and planners aiming to enhance climate resilience and food security.