When is the chilly spring?

Late spring cold refers to the weather phenomenon that the temperature rises rapidly in early spring (generally refers to March) and the temperature in late spring cold (generally refers to April or May) is lower than that in normal years. 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 severe cold in late spring will do harm to agricultural production.