As cities face more frequent and intense heat waves, keeping urban areas cooler is becoming more important for public health and energy efficiency. Roofs can play a big role in this, especially through their color, material, shape, and nearby tree cover. This study looked at how these factors affect roof temperatures during a heatwave in a city with a humid climate. Using advanced airborne imaging tools, researchers measured roof surface temperatures and characteristics like reflectivity (how much sunlight the roof reflects), slope, material, and nearby trees.

They found that roofs that reflect more sunlight—especially in the near-infrared range—stay cooler. Roof slope also matters, and the combination of reflectivity and slope explained most of the temperature differences for large commercial roofs. Trees near buildings helped cool smaller roofs, like those on homes. Interestingly, metal roofs weren’t always cooler—it depended on the specific coating and color.

These findings can help cities make better design choices, like using more reflective roof materials and planting trees strategically, to reduce heat in urban areas. The study also shows how powerful aerial tools can be for tracking and understanding urban heat.