How does Earth's axial tilt affect seasons?

Earth's axial tilt causes seasons by changing the intensity and duration of sunlight received in different regions throughout the year.

The Earth's axis is tilted at an angle of approximately 23.5 degrees relative to its orbit around the Sun. This tilt, combined with the Earth's elliptical orbit, results in varying amounts of sunlight reaching different parts of the Earth at different times of the year. This variation in sunlight is what causes the change in seasons.

During the Earth's orbit around the Sun, the tilt of the axis remains the same, with the North Pole always pointing towards the North Star. This means that at different times of the year, either the Northern Hemisphere or the Southern Hemisphere is tilted more towards the Sun. When a hemisphere is tilted towards the Sun, it receives more direct sunlight and experiences longer daylight hours, leading to warmer temperatures and the summer season. Conversely, when a hemisphere is tilted away from the Sun, it receives less direct sunlight and experiences shorter daylight hours, leading to cooler temperatures and the winter season.

In between these extremes, during the spring and autumn equinoxes, the tilt of the Earth's axis is such that the Sun is directly above the equator. This results in roughly equal day and night across the globe and moderate temperatures, marking the transition between the warm and cool seasons.

The axial tilt also affects the intensity of the seasons. The greater the tilt, the more extreme the seasons can be. For example, regions near the poles experience the most extreme variations in sunlight and therefore have the most pronounced seasons, while regions near the equator, where sunlight is more constant, have little seasonal variation.

In summary, the tilt of the Earth's axis is the primary reason for the change in seasons, as it alters the amount and intensity of sunlight received in different regions throughout the year.