Assessment of Urban Heat Island Effect in Ibadan Metropolis, Oyo State

Rapid urbanisation transforms the thermal environment of cities, producing urban heat islands that elevate surface and air temperatures relative to surrounding rural areas. This study assesses the urban heat island effect in Ibadan Metropolis, Oyo State, Nigeria's largest city by land area, using remotely sensed land surface temperature data derived from Landsat-8 thermal infrared bands acquired between 2019 and 2023. Land use and land cover maps generated through supervised classification are used to correlate surface temperature patterns with impervious surface coverage, vegetation density, and urban morphology. Ground-truth temperature measurements were collected at 30 monitoring points distributed across central, transitional, and peri-urban zones. Results indicate a mean temperature differential of 4.2 degrees Celsius between the densely built central commercial district and forested peri-urban areas, with maximum differences exceeding 7 degrees Celsius during dry-season afternoons. Areas with high impervious surface fractions and low normalised difference vegetation index scores consistently record the highest land surface temperatures. The study identifies urban green space loss, building material composition, and anthropogenic heat emission as contributing factors. Policy recommendations address urban forest enhancement, cool roof incentives for new construction, and incorporation of green infrastructure standards into Ibadan's revised urban development plan. Keywords: urban heat island, land surface temperature, Ibadan, impervious surfaces, urban greening.