Climate change and rainfall variability in Bida, Nigeria: A three-decade analysis (1991–2020)

Abstract

Climate change has increasingly disrupted hydrometeorological patterns globally, with local manifestations posing severe challenges to agriculture, water supply, and public health. This study investigates the impact of climate change on rainfall variability in Bida, Niger State, Nigeria, over a 30-year period (1991–2020), a region where livelihoods depend heavily on climate-sensitive activities. The study aims to analyze long-term changes in rainfall patterns and examine their relationship with temperature and relative humidity to understand localized climatic shifts and inform adaptation planning. Historical climate data were sourced from the ERA5 Reanalysis Dataset and NASA POWER platform, covering rainfall, temperature, and relative humidity. These datasets were aggregated into annual and decadal series and subjected to descriptive statistical analysis, including mean, standard deviation, and coefficient of variation. Seasonal trends were also examined by distinguishing between wet and dry periods. Results show a steady decline in average annual rainfall by 1.083 mm over the three decades, coupled with a 1.03°C increase in average annual temperature. Relative humidity exhibited slight fluctuations, with more variability observed in recent years. The most significant rainfall was recorded in 1995 (5.00 mm), while the lowest was in 1999 (0.89 mm). Temperature peaked in 2005 at 28.55°C. Seasonal analyses further indicate reduced rainy season rainfall and rising dry season temperatures. The findings confirm a pattern of increasing climatic stress in Bida, characterized by reduced water availability and elevated heat levels. These trends highlight the urgent need for climate-resilient policies, especially in agriculture, water resource management, and public health planning. Promoting climate-smart agriculture, improving water infrastructure, and strengthening local climate data systems are recommended for building regional resilience to ongoing climate variability.