Shengshi, why does the weather forecast say the number of winds?

The magnitude of the wind is graded, the smallest is the magnitude, and the largest is the magnitude. The wind is good for us, but it is also harmful. Strong winds will blow down crops, trees and houses. The stronger the wind, the more destructive it is. The series of the wind indicates the magnitude of the wind. If people can know the magnitude of the wind in advance, they can prepare for the wind and ensure safe production.