Why is the weather so bad in the north, hotter in summer and colder in winter than in the south?

In winter, the height of the sun in the north is very low, and the sunshine time is short. Due to the influence of Siberian cold high pressure, the temperature drops rapidly, but it is not obvious in the south. Although the height of the sun in the north is lower than that in the south in summer, it is not as obvious as in winter, and the day is longer than that in the south, which reduces the influence of the low sun height. In addition, the warm and humid summer monsoon also reduces the temperature difference between north and south in summer.