Understanding the cooling capacity and its potential drivers in urban forests at the single tree and cluster scales

•Unmanned aerial vehicle image can be used well for tree species classification.•The cooling intensity of trees varied greatly ranging from 5.05 °C to 16.12 °C.•The tree canopy coverage threshold (40%) was determined for affecting cooling intensity.•The spatial distribution of tree species had significant impact on the cooling intensity.•Our founding could be used for the design of urban forest for maximizing cooling service.