Accelerated urbanization and climate change have made many cities vulnerable to high summer temperatures, putting residents’ lives at risk. Rapid urban growth alters microclimates and ecosystems by replacing permeable, green spaces with impermeable surfaces. These surfaces, more efficient at heat transfer than water, absorb and store solar radiation, affecting surface energy balance. LST (Land Surface Temperature) influences an urban resident’s comfort in extreme heat. This study examines how changes in LULC impact midsummer LST and analyzes the botanical garden in the Mirpur neighborhood and its 800-m buffer zone for green space cooling efficiency (GCE), park cooling intensity, and green space cooling gradient (GCG).We compute the LST of the Botanical Garden and its surrounding buffer zone, correlating it with land use metrics like NDVI, NDBI, and NDWI, using Landsat 8 data from summer 2024. ArcGIS is employed to analyze the correlation between LST and relevant indicators. NDVI showed a negative correlation with LST, while NDBI had a strong positive correlation. NDWI displayed a weak correlation. Results indicate that LST increases within the buffer zones, peaking at the farthest point. The park’s cooling intensity shows that the botanical garden significantly cools its nearby area, with the effect decreasing as distance increases, though it remains noticeable. The GCE value of 6.72 m2 suggests that each square meter of green space cools 6.72 square meters of the surrounding area. The GCG value of 0.04 °C/m2 indicates a relatively slow decrease in cooling effect, meaning the botanical garden has a notable cooling influence extending across its buffer area. This study emphasizes the importance of green spaces in mitigating urban heat and create a healthy and comfortable thermal environment.