What is the main reason for warmer temperatures in summer? Earth is closer to the Sun. The Sun shines more directly on the hemisphere because the Earth is tilted towards the Sun. The days are shorter. Earth spins faster.

The main reason for warmer temperatures in summer is that the Sun shines more directly on the hemisphere because the Earth is tilted towards the Sun. This tilt causes the Sun's rays to hit the Earth at a more direct angle, resulting in increased solar energy and warmer temperatures.