Why is the weather so cold?

The changes in the four seasons of the year change with the distance of the earth's orbit around the sun. The earth's orbit around the sun is an elliptical orbit, so the earth has an angle relative to the sun. Perihelion and aphelion, when the sun moves to perihelion, that is, in winter, the daytime becomes shorter and the time when the sun shines directly on the earth's surface becomes shorter, so the earth receives less heat from the sun, so the weather becomes It's cold.