Seasons on Earth

As Earth travels on its orbit around the sun, some changes occur on certain portions of Earth. Such changes are caused by the varying amounts of sunlight around Earth during the year. These regular repeated changes are referred to as the seasons of the year. They are brought about by two factors: the inclination of Earth’s axis as it rotates and Earth’s revolution around the sun.

Earth’s axis is tilted or slanted by 23.5° relative to vertical. The tilt is oriented toward the sun in certain months of the year and is oriented away from the sun in other months. This tilting of Earth’s axis and the revolution of Earth around the sun cause the difference in the amount of light and heat received from the sun by the different parts of Earth. If Earth is not tilted, then the various parts of Earth would receive the same amount of light during its travel around the sun.