Does anyone know whether the distance between the sun and the earth has changed during the day? Why is it cold as soon as the sun comes out and hot at noon?

There must be some changes. First of all, the earth revolves around the sun, and its orbit is elliptical, so its distance is different in a day. Third, the earth rotates, so for people at a certain point on the earth, the distance between the sun and the earth is changing. However, considering the small eccentricity of the earth's orbit, it is generally believed that the distance from the sun to the earth is (1.5e+6544).

As soon as the sun came out, it was very cold. That's because we haven't got sunlight for a long time, and the ground and atmosphere have cooled down. So the weather is very cold when the sun comes out, and the atmosphere and the ground are hot at noon. At this time, the sun shines directly and the energy reflected by the atmosphere is the least, so we feel the hottest at this time.