Climate change has significantly altered global weather patterns, with notable impacts in Nigeria. The main objective of this study was to examine the trends, variability, and homogeneity in temperature and rainfall in Nigeria. The study analysed temperature and rainfall trends from 1901 to 2021 using the variability test, trends test, and homogeneity tests. The results show that the north is the most unstable and the south most stable. The north experiences the least amount of rainfall each year, while the southern region experiences the highest amount of rainfall. The test results for Mann-Kendall (MK) showed that the temperature trend in Nigeria has considerably accelerated. Conversely, patterns of rainfall indicate a general decline, particularly in central and southern regions of the country. The Theil Sen’s slope estimator (TSE) revealed that the two regions with the greatest shifts in rising temperature and decreasing rainfall are Sokoto (north) and Akwa Ibom (south). Homogeneity tests identified temperature change points occurring in northern Nigeria between 1981 and 1995, while southern Nigeria experienced abrupt warming around 1997–2000.