Originally Posted by Nicolas Naranja

This is true. I'm sure most of us remember from science class that warm air rises and cool air sinks. During a radiational cooling event the surface loses its heat to the atmosphere and if there is no wind the air closest to the surface can get quite cold. If there is wind it mixes the warmer air aloft with the cooler air at the surface. In Florida, we have a bunch of agricultural weather stations that let you look at temps at 60cm, 2m and 10m and the temperature differences may be as much as 6-7 degrees fahrenheit between the 60cm and the 10m.