SPATIOTEMPORAL TRENDS AND VARIABILITY OF RAINFALL ANOMALIES ACROSS THE AGRO-ECOLOGICAL ZONES OF NORTHWESTERN NIGERIA

Abstract

This study analysed rainfall variability across selected states in northwestern Nigeria, namely Kaduna, Katsina, and Sokoto. Monthly rainfall records for the selected states were collected from secondary sources for a period of thirty (30) years (1995-2025) from the Nigerian Meteorological Agency (NIMET) at Nnamdi Azikiwe International Airport, Abuja. The objective is to determine the trends and variability of rainfall anomalies over a specific period. Both descriptive and inferential statistics were used. The trends, anomalies, and relationships among selected weather elements, particularly rainfall, were analysed. The statistical analyses employed were trend analysis, anomaly analysis, correlation analysis, and analysis of variance (ANOVA). Statistical Package for the Social Sciences (SPSS) was utilised. The results showed generally similar monthly rainfall trends across the states, while annual rainfall exhibited fluctuations and departures (anomalies) from the mean values throughout the study period (1995–2025). The study reveals a weak positive statistical relationship in rainfall within the states at the 95% confidence level. The study reveals a significant difference in rainfall across the states during the study period (1995- 2025). The study concludes that the observed variability in rainfall patterns over the years provides evidence of climate change in the agro-ecological region. The study concludes that the observed variability in rainfall patterns over the years provides evidence of climate change in the agro-ecological region.