Climatic Variability of Rainfall and Temperature Over Selected Stations in Africa Sub-regions

Abstract Research has shown that Africa climate experience unpredictability presents serious obstacles to agriculture, environmental sustainability, and water resource management. For this research 26 years (2000–2025) dataset of MERRA-2 reanalysis data were used, to evaluate the spatial and temporal variability of temperature and rainfall throughout the following stations: Abuja, Cairo, Luanda, Nairobi, and Johannesburg. A one-way ANOVA, descriptive statistics, data quality control, and the Mann-Kendall test using Sen's slope estimator were all used for the analysis. The results showed significant environmental variety, with temperatures ranging from 289.6 to 299.2 K (16.5–26.1°C) and annual rainfall from less than 50 mm in Cairo to more than 2,400 mm in Abuja. The temperature rose by 0.1–0.9 K while regional rainfall increased by 2–10%, with the biggest increases happening in the direction of Nairobi and Johannesburg. There were significant inter-station variances (p < 0.001), ranging from 243.34 to 1,694.54 mm in rainfall, 9.06°C in maximum temperature differences, and 13.88°C in minimum temperature differences. Highly substantial geographical variation in maximum (F = 646.859) and minimum (F = 1371.112) temperatures was verified by one-way ANOVA (p < 0.001). Sen's slopes ranged from − 3.63 to 5.93, indicating significant natural climate variability, despite the Mann-Kendall test showing no statistically significant monthly rainfall trends. Growing climate variability is highlighted by rising temperature trends and more frequent rainfall extremes after 2010. This knowledge is vital for agricultural planning, water resource management, climate adaption, and catastrophe risk reduction throughout Africa.