Why is foggy noon often sunny?

When the water content in the lower air is high, the water will condense into fog when the temperature drops suddenly at night. Fog has radiation fog, that is, fog formed under relatively clear and stable conditions. As long as the sun comes out and the temperature rises, the fog will naturally disappear.

In autumn and winter, after the cold air in the north goes south, as the weather turns fine and sunny, the moisture content in the air gradually increases, which is easy to form radiation fog, so the fog in autumn and winter can often predict the good weather tomorrow.

To accurately understand the sky through fog, we must also look at the duration of fog. Radiation fog is caused by cold weather and water vapor condensation, so it disappears when the temperature rises during the day, and the weather is fine; On the other hand, "fog is rain." If the fog doesn't disperse during the day, it may rain the next day, so the folk proverb says, "The fog doesn't reach noon, and the rain will ring after noon."

Extended data:

Classification of fog:

1. According to the different formation processes, fog can be divided into radiation fog, advection fog fog, uphill fog and evaporation fog.

Second, according to the state of matter, there are three kinds of fog, ice fog and water-ice mixed fog, which are composed of water droplets, ice, crystals and water droplets with ice crystals respectively.

Third, the synoptic classification of fog divides fog into two categories: air mass fog and frontal fog. In addition, people usually call the fog that occurs at sea "sea fog".

China Net-Known as "Fog Cave"

China Net-Relationship between Fog and Weather