What does it mean that the wheat harvest rains in March and February is the most afraid of cold?

"March wheat harvests rain, and February is the most afraid of cold" means that if the weather is stable in March, wheat usually has a good yield, especially after rain, which can effectively replenish water to wheat. But in February, when the weather is warm and cold, the newly grown leaves of wheat have poor resistance and are easy to freeze to death, and pests and diseases may break out. The turning green period of wheat usually occurs in March. During this period, the weather is unstable, and what I fear most is the "cold spring". Sudden cold current will cause freezing damage to wheat, especially affecting yield. During this period, we should pay more attention to the weather changes and water the wheat before cooling down. The heat capacity of water is greater than that of air and soil. This method can control the temperature change and keep the constant temperature before the cold current comes in early spring. If this happens, it is necessary to properly supplement fertilizer to prevent pests and diseases.