入冬之后，我国许多地区，尤其是在北方都有可能普降瑞雪．雪和雨一样，都来自云中，同属降水．由于云内或云下的温度高低有别，导致雪和雨的形态不同．当云内和云下的温度都低于０℃时，空气中的水汽不会液化成水滴，而是直接凝华成冰晶体．加之冬天地面气温很低，雪在下降过 After entering the winter, many areas in our country, especially in the north, are likely to reduce snow. Like snow and rain, it comes from the clouds and belongs to precipitation. Because the temperature inside or below the cloud is different, the shape of snow and rain is different. When the temperature in the cloud and below the cloud is below 0°C, the water vapor in the air will not liquefy into water droplets, but will directly degenerate into ice crystals. In addition, the winter ground temperature is very low and the snow is falling.