Why are seasons opposite?

Seasons are opposite due to the Earth's tilt on its axis. The Earth revolves around the Sun once a year, and during that time, different parts of the Earth are tilted more or less towards the Sun. This tilt is what causes the seasons.

When the Northern Hemisphere is tilted towards the Sun, it receives more direct sunlight, which results in summer. During this time, the Southern Hemisphere is tilted away from the Sun, receiving less direct sunlight, and is experiencing winter.

When the Southern Hemisphere is tilted towards the Sun, it receives more direct sunlight, resulting in summer there, while the Northern Hemisphere experiences winter.

As the Earth revolves around the Sun and the tilt reverses, the seasons change, resulting in the opposite seasons in the Northern and Southern Hemispheres.