One of the meteorological phenomena more complicated to predict it is without a doubt the fog. It is nothing more than the formation of a large cloud at ground level with a 100% humidity. It is usually quite frequent in many areas of the country and the months in which it usually manifests itself more frequently. it's december and january. Next I will tell you a little more about this curious and dangerous atmospheric phenomenon.
Fog forms in situations of absolute stability, without any wind and with the presence of an anticyclone. Fog can never form with a squall. This phenomenon originates when the temperature is lower in the lower layers than the higher ones, that is, when it is colder in the capital than in the mountains or in the mountains.
According to data managed by the AEMET, the city with the most foggy days a year is ValladolidZaragoza and Salamanca follow. However, there are areas of the island of Tenerife, in which you can register an average of 60 days a year with fog banks.
The fog is totally harmless to health, despite what many people may think. On days when there is fog, as there is no wind in the air, the pollution is much greater than a normal day, however fog is not bad for the body. The air that is going to breathe inside a fog bank is the same in the event that this phenomenon did not occur, the difference is that a higher concentration of water vapor.
I hope I have clarified many of your doubts about this common meteorological phenomenon in the winter months and that makes visibility so difficult for drivers, being a real danger for driving.