Why has it been raining continuously recently?

The reason why it has been raining recently is the frequent cold air activity. According to the Meteorological Observatory, from 17 to 19, there are small to medium snow (rain) or sleet in parts of northeastern Qinghai-Tibet Plateau, eastern Inner Mongolia, and north-central Northeast China. There are small to moderate rains or thunderstorms in northwestern Xinjiang, southeastern Tibet, southern Northeast China, most of southwestern China, south-central Jiangnan, southern China and Taiwan Province Province, among which there is heavy rain in parts of southern China. If you still want to know the weather situation in a specific area, please refer to:/weather forecast 15 days.