The design of urban green spaces and water resources at the micro scale, as well as their spatial configurations at the macro scale, is of utmost importance. The selection of functional landscape elements in such vulnerable areas should aim to enhance their cooling effects. Additionally, analyzing the land uses surrounding these areas through Remote Sensing and Geographic Information Technologies effectively contribute to determine their cooling effect by the help of various landscape metrics. In this study, urban green spaces over 25,000 m2 and their surroundings existing in different locations on the Asian side of Istanbul—a globally significant city in terms of population and population density—were investigated for urban heat island effects using Landsat-8 satellite imagery and 3 different landscape metrics. Visual and statistical analyses were conducted, and the findings were compared with similar recent studies in other global megacities. Across the Asian side of Istanbul, a temperature difference of over 5 °C was identified between impervious surfaces and all green spaces. The findings point out that the features of urban green spaces like size, landscape features, and surrounding land uses have varying effects on their cooling capacity. As the distance from urban green areas increases, the land surface temperature value rises. The results indicate that parks located along air corridors and relatively close to coastal areas exhibit stronger cooling effects.