How does dew form on flowers and trees in autumn morning?

In spring and autumn, the temperature changes greatly during the day and at night. During the day, the sun heats the earth and the air, and the ground and trees evaporate a lot of water vapor. At night, the earth began to cool down, the fastest cooling is stones and trees, but the heat radiation in the air is slow, and the air is not easy to cool down. The water vapor in the air comes into contact with the first cooled stone or tree and condenses into small water droplets, which is dew. It's still very cold in the morning, and dew will remain on the grass or stones.