Question

Why is it cooler in the evening or morning than in the afternoon?

Answer 1

The earth gets heated with the rays till noon. In the morning the sun starts rising but in the noon the sun is at the top.
At noon direct rays of sun rays hit the surface of the earth while in morning and evening only a part of the rays hit the surface of the earth.
The temperature of the air in the morning is cold. The sun then heats the air and it gets very hot till noon.
After the noon, the sun starts going away which again starts to cool the air in the atmosphere. After some time in the evening, most of the air becomes cooler.
This is the reason why the temperature at noon is hotter than morning and evening.