Some assume our planet's changing distance from the sun causes the change in the seasons. That's logical, but not the case for Earth. Instead, Earth has seasons because our planet's axis of rotation is tilted at an angle of 23.5 degrees relative to our orbital plane, that is, the plane of Earth's orbit around the sun.

The tilt of the (Moon) / (Earth) causes the sun to appear in the sky at a slightly different spot every day.

The Earth has an elliptical orbit around our Sun. This being said, the Earth is at its closest point distance wise to the Sun in January (called the Perihelion) and the furthest in July (the Aphelion). But this distance change is not great enough to cause any substantial difference in our climate.

Earth's seasons are caused by the tilt of its rotation axis, which is why the seasons are the opposite in the two hemispheres. The tilt of the axis causes sunlight to fall differently on Earth at different times of the years.

As the earth spins on its axis, producing night and day, it also moves about the sun in an elliptical (elongated circle) orbit that requires about 365 1/4 days to complete. The earth's spin axis is tilted with respect to its orbital plane. This is what causes the seasons.

The reasons for the Earth experiencing seasons are revolution, rotation, tilt, axial parallelism, and sphericity – yikes! and I thought it had only to do with the tilt of the Earth! Let's first look at revolution, which is Earth's orbit around the sun.

As Earth orbits the Sun, its tilted axis always points in the same direction. So, throughout the year, different parts of Earth get the Sun's direct rays. Sometimes it is the North Pole tilting toward the Sun (around June) and sometimes it is the South Pole tilting toward the Sun (around December).