What causes the seasons on Earth?

The seasons on Earth are caused by the tilt of the Earth’s axis and its orbit around the Sun. The Earth is tilted at an angle of about 23.5 degrees, so as it orbits the Sun, different parts of the planet receive varying amounts of sunlight throughout the year. When the Northern Hemisphere is tilted toward the Sun, it experiences summer, while the Southern Hemisphere experiences winter, and vice versa. The equinoxes mark the points in the year when both hemispheres receive equal amounts of sunlight, resulting in spring and autumn.