Spatiotemporal dynamics of the interactions between urban surface temperature and extreme hourly rainfall in Nigerian cities

This study provides the first high-resolution, multi-city assessment of extreme hourly rainfall and land surface temperature (LST) interactions in Nigeria, utilizing ERA5 hourly rainfall, MODIS LST (MOD11A1) and LC (MCD12Q1) data from 2001 to 2023. Prior research across West Africa has been constrained by low temporal resolution, limited spatial coverage, or single-city focus; this study addresses these gaps by applying a percentile-based framework (95th and 99th percentiles) across ten climatically diverse Nigerian cities spanning coastal, inland, elevated, and semi-arid zones. Using quantile regression, the study uncovered that rainfall–LST relationships vary not only by location but also by intensity level: coastal cities like Lagos (Q0.9 slope ≈ − 11.07 °C/mm, R² = 0.038) and Aba (Q0.9 slope ≈ − 4.72 °C/mm) show strong inverse relationships, suggesting rainfall-induced surface cooling, particularly at high extremes. In contrast, inland and elevated cities such as Ilorin (Q0.9 slope ≈ + 17.00 °C/mm, R² = 0.145) and Jos (Q0.9 slope ≈ + 18.15 °C/mm, R² = 0.233) exhibit positive correlations, indicating that higher surface warming enhances rainfall through convection or orographic processes. Ilorin also recorded the highest decadal rainfall intensification (+ 0.55 mm/hour), with sharp increases observed in Ibadan and Aba ( > + 0.45 mm/hour). Meanwhile, urban heat island effects are intensifying, particularly in Abuja and Benin City, where LST trends exceed + 0.25 °C/year. These findings highlight the nonlinear, asymmetric, and location-specific nature of climate-rainfall interactions in rapidly urbanizing environments. The study not only demonstrates the novel use of city-level ERA5 hourly data in West Africa but also underscores the urgent need for tailored urban adaptation strategies that address compounding heat and flood risks.