Why is the weather hot and cold?

You can imagine it as a cold front. The warm front is fighting fiercely. Today, the cold front won and the temperature dropped. In a few days, the warm front gathered strength, and then fought to repel the cold front, and the temperature warmed up. Because the general environment and trend is that the warm front will eventually replace the cold front to occupy this area (the direct point of the sun is constantly moving northward), and the strength of the cold front will become weaker and weaker, from the initial large-scale invasion to the subsequent sneak attack from time to time, and then slowly retreat. So in this transition period, the temperature will be hot and cold, accompanied by more precipitation. In short, it makes more sense—

Please accept it, thank you!