Why is the solar term not equal to the height angle of the noon sun and "Qingming" is cold dew?

Qingming: fighting refers to Ding. The solar calendar is 15. At this time, the climate is fresh and warm, flowers and trees grow new branches, everything begins to grow, and farmers are busy ploughing and planting in spring. Once upon a time, on this day in Tomb-Sweeping Day, some families would plant willows at the door and go for an outing to sweep the graves in the suburbs. This is an ancient custom.

Cold dew: fighting nails. The solar line is 195. After the white dew, the weather turned cold and dew began to appear. When the dew is cold, there is much dew and the temperature is low. So some people say that cold is dew, white first and then cold, which means that the climate will gradually turn cold. Water vapor condenses into dew.

From the solstice in winter to the solstice in summer, the sun height in the northern hemisphere becomes higher, and vice versa. Therefore, when the height of the sun is equal, it is the symmetrical point of the "winter solstice-summer solstice" line in the above picture.

Therefore, the height of the sun in Qingming and Bailu is the same, as is the height of the sun in Cold Dew and Sting.