The most important things needed to make radiation fog are really wet soil, light wind, clear skies, and a low afternoon dewpoint. The more things that are present, the more likely you will see fog. Really wet soils continuously put moisture into the air, making sure the dewpoint depression (difference between temperature and dewpoint) will remain low. Light wind reduces the amount of mixing of air near the earth. If winds are light, moisture evaporating from the surface will remain near the surface and not mix with drier air aloft. If wind is calm, expect fog to be very close to the ground or not there. In a calm situation with a low dewpoint depression and moist soils, expect a thick dew or frost instead of radiation fog.
Other kinds of fog in later posts. =^._.^= meow i made it don’t take credit!!!!!