Describe the conditions necessary for the formation...

Dew forms when the radiational cooling of objects near or on the ground also cools the shallow layer of air that comes in contact with them, causing the condensation of some water vapor. The atmosphere supplies most of the water vapor, but some also can diffuse up through the soil and condense on the ground. The temperature at which condensation begins is termed the dew point. The best conditions for dew formation are high humidity in the lowest layers of air and the absence of a strong wind, which would create a larger, more homogeneous layer of air.