The temperature on Earthˇs surface is directly related to the angle at which the Sunˇs rays penetrate the atmosphere. Where this angle of incidence is low when the rays skim the groundsolar energy is dispersed. It is hottest where the rays reach the ground at a 90 angle..Because of Earthˇs inclination, solar light reaches the Northern Hemisphere at a high angle during the summer. At the same time, rays hit the Southern Hemisphere at a low angle, and it is winter there.