Why do you say "dew will make it clear, and frost will make it clear again"?

There are two weather proverbs: it's sunny when the dew shows, and it's sunny when the frost shows. Both proverbs mean that when fog dew or thick frost appears in the evening or morning, the next day is usually sunny.

When there is frost, it means that the weather is clear and cold at night, the atmosphere is stable, and the ground radiation cools down strongly. This usually happens when the cold and high pressure are under control, so it often lasts for a few days in sunny days.

Thick frost often appears at night after the cold current, when the sky is clear and partly cloudy, the wind speed decreases and the temperature drops obviously. At this time, the ground is near the center of high pressure, and the weather is relatively stable under the control of the northwest airflow with consistent high altitude, so it will generally continue to be sunny after frost.

Extended data:

Weather proverb:

1, get up early and float away, and sun the dog at noon.

The wise ancients learned from their daily life and work that in late autumn, if the clouds break away in the morning, it will be very hot at noon

The principle is that the sun rises in the morning and the ground temperature rises, which leads to the gradual increase of the near-ground temperature, which will evaporate the water, fog and moisture on the ground. These water vapor will rise and then form stratus clouds. Because of its low height, this stratus cloud seems to move quickly, which will form a situation of "floating clouds walking".

The formation of this stratus cloud is related to temperature. With the sun's rays, the temperature rises, and the stratus will disappear continuously. Finally, it will form a blue sky scene. Without the refraction of clouds, the sunlight will be very strong, so it will be very hot at noon, so hot that even dogs will stick out their tongues to dissipate heat.

It's okay when the spider opens the net, but it rains when the spider closes the net.

In ancient times, every summer, with the high temperature, thunderstorms have always plagued the people. Bad weather not only affects people's lives, but also affects people's labor achievements.

The ancients found that when the weather was clear, spiders would try to open their nets to hunt. When it is about to rain or when it rains, the spider's web will change direction, and the web surface will change to form parallel to the raindrops. Rain will hardly destroy cobwebs. This situation is tried and tested, and curious friends can observe it in their daily lives.