Cities across the world are expanding at an unprecedented rate, especially in developing regions, where urban growth often comes at the cost of green spaces. This study takes a closer look at Guwahati, a swiftly urban growth city in Northeast India, to explore how land cover has experienced over the last thirty years. Using multi-temporal Landsat satellite imagery, we analyzed both the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Built-Up Index (NDBI) for the years 1993, 2003, 2013, and 2023. The results show a dramatic shift-built-up areas expanded from just 21.09 km2 in 1993 to 106.67 km2 in 2023, while green spaces declined by nearly 39%. To assess the thermal consequences of these changes, we used Land Surface Temperature (LST) data from Landsat 8 for 2013 and 2023. Our analysis revealed that the area affected by Urban Heat Spots (UHS), zones of concentrated surface warmth, rose by 22.63%, mainly in dense, newly developed zones. This rise points to the growing influence of impervious surfaces and shrinking vegetation on local microclimates. Together, these insights highlight the importance of city growth approaches that champion ecological balance. The approaches and insights from this study provide a practical framework not just for Guwahati, but for other fast-growing cities grappling with similar challenges. As the world navigates climate risks and rapid urbanization, maintaining green cover is no longer optional; it’s essential.