Seasons

Seasons are caused by the Earth´s rotation around a tilted axix and the Earth´s revolution.

When the northern hemisphere is tilted towards the Sun it receives more solar energy than the southern hemisphere, it is summer in the northern hemisphere and winter in the Southern. The Summer solstice is the day with more daylight hours in the year, 21st of June.
As the Earth continues on its orbit at the Sun both hemispheres receive equal amount of sunlight. Days become longer in the southern hemisphere and shorter northern hemisphere, it is Autumn in the northern hemisphere. The two days in the year when the day and the night last the same are the equinoxes : 21st march, 22nd september.