Radiation Fog (Nano)
From SKYbrary Wiki
Radiation Fog - Formation
On a cloudless night, especially within a high pressure system, the land surface loses heat to the atmosphere by radiation and cools. Moist air in contact with cooling surface also cools and when the temperature falls below the dew point for that air, fog forms. The three conditions for radiation fog are: clear skies, moist air, and a light wind.
Learn more about Fog