在春季天气回暖过程中,常因冷空气的侵入,使气温明显降低,对作物造成危害,这种“前春暖,后春寒”的天气称为倒春寒。农业气象试验指出,“倒春寒”的标准为日平均气温≤12℃,维持期≥3天。通常,人们将进入3月作为春天的开始。春季气候的最大的特点就是乍暖还寒:一是春季的气温日夜温差较大;二是春季冷空气活动频繁,天气变化较 In the spring weather warmer process, often due to the intrusion of cold air, so that the temperature decreased significantly, causing harm to crops, this “before spring, after spring ” weather is called late spring cold. Agrometeorological experiments pointed out that “late spring ” standard for the average daily temperature <12 ℃, maintenance period ≥ 3 days. Normally people will enter March as the beginning of spring. The biggest feature of the spring climate is warm and cold: First, the temperature in spring temperature difference between day and night larger; Second, frequent cold air in spring, the weather changes more