What is the tilt of the earth as it rotates on its axis?

The tilt of Earth as it rotates on its axis is approximately 23 degrees. More precisely, Earth’s axial tilt, or obliquity, is about 23.4 degrees relative to the perpendicular to its orbital plane.

This tilt is the main reason Earth has seasons. As Earth travels around the Sun, each hemisphere alternately leans toward and away from the Sun, changing the angle and duration of sunlight it receives. Summer occurs when a hemisphere is tilted toward the Sun; winter occurs when it is tilted away.

A common misconception is that seasons are caused primarily by Earth being closer to or farther from the Sun. In reality, the axial tilt has the dominant effect. Earth’s tilt is not perfectly constant: it slowly varies between roughly 22.1 and 24.5 degrees over a cycle lasting about 41,000 years. The direction of the tilted axis also changes gradually through axial precession, a cycle of about 26,000 years.