Rain occurs when water vapor¹ in the atmosphere cools and condenses into tiny droplets², forming clouds. When these droplets combine and grow heavy enough, they fall to the ground as precipitation, which we call rain. This process is part of the water cycle, where water evaporates from surfaces like oceans, lakes, and rivers, rises into the atmosphere, and eventually returns to Earth as rain.

下雨是因为大气中的水蒸气冷却并凝结成小水滴，形成云。当这些水滴结合并变得足够重时，它们就会以降水形式落到地面，这就是雨。这个过程是水循环的一部分，水从海洋、湖泊和河流等表面蒸发，上升到大气中，最终以雨的形式回到地球。