The surface is heated by the Sun and some of that heat radiates back into the air. This makes the temperature higher near the surface than at higher altitudes.
Paul started at the base of a mountain and climbed to its peak. The sky was clear and the sun was beating down on him all day. However, he noticed there was a clear temperature difference between the surface's temperature and the temperature at the top of the mountain peak. Where would he feel more heat?

1) Surface
2) Mountain Peak