Axial tilt

Axial tilt is when the Earth's axis is tilted at an angle. This angle is what determines the amount of daylight we receive each day and how much the seasons will change throughout the year. The Earth's axis is tilted at an angle of about 23.5 degrees from the vertical, and it's this tilt that causes the different seasons we experience. In the summer, the sun is higher in the sky and so the days are longer, and it's warmer because the sun's rays spend more time hitting the Earth. In the winter, the sun is lower in the sky and so the days are shorter and it's colder because the sun's rays spend less time hitting the Earth.