What is the common sense of observing the weather?

With the development of science, people have gradually mastered the ins and outs of rain and the law of its formation. There are no clouds in the sky and it doesn't rain, because clouds are the precursor of rain, and rain falls from the clouds. Sunlight shines on land and sea, and water is evaporated into water vapor and enters the atmosphere, which condenses to form tiny water droplets. Clouds are generally "warm clouds" composed of suspended polymerized water droplets with a temperature above 0℃, and the other is "Leng Yun" composed of relatively cold water droplets and small ice crystals with a temperature below 0℃. There are more warm clouds in summer and more Leng Yun in winter. When the temperature in the cold cloud is lower than -20℃, small ice crystals absorb the water vapor evaporated from nearby water droplets, and their volume increases. They "travel" up and down in the clouds and collide with each other. The rising airflow can't hold ice crystals, so it falls from the sky. This is snowflake. If in the process of falling, through the transformation of ice water, rainfall is formed.

Nowadays, people's beautiful fantasies and hopes for thousands of years have become a reality.