Seasons happen because Earth spins around an axis which is tilted at an angle of 23.5 degrees. Because of this spinning, parts of Earth gets nearer or more distant from the Sun. Around the June Solstice, the Northern Hemisphere is turned towards the Sun, and gets more direct Sun rays. Because of this, the Northern Hemisphere experience summer in June, July and August. Opposite from this, for the people of South Hemisphere, June, July and August represent the months of winter. Around the December Solstice, the situation completely changes: Southern Hemisphere is turned towards the Sun, and Northern is more distant.
