How is weather created?

Air contains water vapor that absorbs energy well, and the water vapor in the air can be continuously replenished. In a continuous cycle, water evaporates from land and sea and collects into clouds. Then rain, snow or other forms of precipitation are produced, and the entire process is self-cyclical.

Water molecules in the atmosphere are constantly changing back and forth between three states: gas, liquid and solid. Rain falling from a cloud means that more water molecules leave the gaseous state and form droplets (condensation) than water molecules enter the gaseous state (evaporation).

These two processes, condensation and evaporation, are going on all the time in the air around us, but the speed will vary depending on the temperature. For example, on a cloudless and sunny day, heat accelerates the rate of evaporation, preventing small water droplets in the air from surviving for too long. So, there are more water molecules returning as water vapor than there are in the form of small water droplets. As the air cools, the rate of evaporation decreases until fewer water molecules evaporate than condense: at this point, the air is said to be saturated, and the water vapor usually condenses into small droplets, forming clouds, mist, and fog.