The average air temperature at the surrounding areas outside near the sites was 32.78 C, at 1500h, with relatively small deviation from site during the period of measurement. The average cooling effect in all sites was about 2.8 K, ranging from as 1 K in a street with heavy traffic to as high as 4K in the smallest garden (0.15ha). the width of the sites ranges from 20 to 60 m.