When the air temperature increases, the temperature of the soil increases as well, usually more than the air temperature itself.
When the air temperature decreases, the temperature of the soil decreases too, very often more in lesser amount than the air temperature itself.
Both the air and the soil are able to increase and decrease temperature very quickly. The air though is able to change its temperature quicker, while the soil needs a little more time because it is able to accumulate certain amounts of heat for some period of time.
