It's spring, why is it still so cold?

Late spring cold refers to the weather phenomenon that the temperature rises rapidly in early spring (generally refers to March) and the temperature is lower than normal in late spring (generally refers to April or May). Long-term rainy weather or frequent cold air intrusion, or under the control of continuous cold and high pressure, strong radiation cooling in sunny nights is easy to cause late spring cold. The climate is changeable in early spring. If the cold air is strong, the temperature can drop to below 10℃, even in rainy and snowy weather. At this time, it is often sunny during the day, which makes people feel that "warm wind makes tourists drunk", but it is chilly in the morning and evening, which makes people feel "chilly in spring". This unpredictable "fickle" weather is what is commonly called "cold spring". It is easy to adversely affect agricultural production and residents' lives. Late spring chill not only exists in China, but also occurs in Japan, North Korea, India and the United States. The reasons are not complicated. Spring in China (around March) is a transitional period of cold wind in winter and late spring in summer. During this period, cold air from the northwest often intrudes intermittently, and the cold air goes south and sticks to the warm and humid airflow in the south, resulting in continuous low temperature and rainy weather. Generally speaking, when the ten-day average temperature is more than 2℃ lower than normal, there will be more serious late spring cold. The later the cold air goes south, the greater the intensity and the wider the cooling range, and the greater the possibility of cold in Chun Xue.