Earth Rotation and Seasonal Changes
The Earth’s axis of rotation is tilted at an angle of about 23.5 ° to the orbital axis. Because of this inclination, seasonal changes occur like as spring, summer, autumn and winter.
The sun illuminates the northern hemisphere more in June-August. So, the northern hemisphere becomes summer and the southern hemisphere becomes winter. Six months later, the sun will illuminates the southern hemisphere more. So, the northern hemisphere will be winter and the southern hemisphere will be summer.
Is it hot in the summer because the earth gets closer to the sun?
In the northern hemisphere, the sun is a little further away in summer.
The reason why the summer is hot is not because of the distance from the sun, but the high altitude of the sun. Because of the high altitude of the sun, the amount of solar radiation per unit area is greater.