Covering and method for promoting local rainfall are provided. The covering has a skin to cover a field that can get thermal energy. An edge part of the skin is installed at a surface of the field, and the inner part of the skin surrounded by the edge part can be lifted up from the surface to form a space to store air. The covered air receives thermal energy and the skin prevents air convection and reduces thermal energy loss, thereby generating a temperature difference between the inside and outside of the skin. By utilizing buoyancy resulted from the air temperature difference to lift up the inner part of the skin, a huge space is formed to contain a large amount of air. Thereafter, the covered air continues to receive thermal energy, causing huge thermal energy to be stored in the covered air, which is then used to promote rainfall.
