Explanation:

The amount of insolation received on the earth’s surface is not uniform everywhere. It varies according to the place and time. When the tropical regions receive maximum annual insolation, it gradually decreases towards the poles. Insolation is more in summers and less in winters. The major factors which influence the amount of insolation received are:

Rotation of the earth on its axis
The angle of incidence of the sun’s rays
Duration of the day
Transparency of the atmosphere