Several environmental and social impacts have emerged from the expansion of the industrial sector, including the high rate of urbanization, which has raised the population density and hence the demand for residential. The density of built-up land affects changes in surface temperature. The greater the urban sprawl, the higher the surface temperature will be. This research examined surface temperature distribution, the density of built-up land in 1999, 2009, and 2019, and the relationship between built-up land and rising surface temperatures. Landsat 5 TM and Landsat 8 OLI TIRS satellite images with remote sensing technology were utilized to map surface temperature distribution and built-up land. This study employed the Google Earth Engine (GEE) platform for temperature transformation and the NDBI, EBBI, BI, and UI transformations for the city propagation influence factors. This study discovered that in 1999, 2009, and 2019, there was a significant relationship between the density of built-up land and the rate at which Semarang's surface temperature changed. The average surface temperature in Semarang rose steadily from 9.1 to 35 °C in 1999 to 11.9 to 35.2 °C in 2009 and a whopping 15.89 to 41 °C in 2019. Correlation coefficients above 0.500 indicate a significant relationship between built-up land and surface temperature based on findings from all-year transformation results. Following the results of the coefficient of determination for each transformation, the impact of built-up land density on surface temperature in the Semarang area was 25% to 50% in 1999, 2009, and 2019.