It is all about the tilt of the Earth's axis. Many people believe that the temperature changes because the Earth is closer to the sun in summer and farther from the sun in winter. In fact, the Earth is farthest from the sun in July and is closest to the sun in January. Earth's tilted axis causes the season. The seasons are reversed in the southern hemisphere because when the northern hemisphere is tilted toward the sun, the southern hemisphere is tilted away from it. This corresponds to the winter and Summer Solstice. For the Southern Hemisphere, this is reversed. For both hemispheres, the earth is 90 degrees away from the sun around March 21 and then again around September 21.

Earth's tilted axis causes the seasons. Throughout the year, different parts of Earth receive the Sun's most direct rays. So, when the North Pole tilts toward the Sun, it's summer in the Northern Hemisphere. And when the South Pole tilts toward the Sun, it's winter in the Northern Hemisphere.For the Southern Hemisphere, this is reversed. For both hemispheres, the earth is 90 degrees away from the sun around March 21 and then again around September 21. The seasons in the Northern Hemisphere are the opposite of those in the Southern Hemisphere. This means that in Argentina and Australia, winter begins in June. The winter solstice in the Southern Hemisphere is June 20 or 21, while the summer solstice, the longest day of the year, is December 21 or 22. For the Northern Hemisphere, the axis points most toward the sun in June and away from the sun around December 21. This corresponds to the Winter and Summer Solstice. For the Southern Hemisphere, this is reversed. The 23.45° tilt between the equator and the orbital plane causes each Hemisphere to lean towards the sun for part of the year. So seasons are reversed between the two Hemispheres. This happens because, as the earth rotates around the sun, it is tilted or leans to one side. This causes one hemisphere to be closer to the sun while the opposite hemisphere faces away. The hemisphere facing the sun experiences summer while the hemisphere facing away from the sun experiences winter.It does so by moving around the Sun; the Earth's spin axis moves much more slowly. Tilting toward the Sun makes summer, and tilting away from the Sun makes winter. The two states are thus Northern Hemisphere summer and Southern Hemisphere winter, and Northern Hemisphere winter and Southern Hemisphere summer. The northern and southern hemispheres always experience opposite seasons. This is because due to the tilted axis of the earth, the North Pole remains inclined towards the sun for a part of the year while the South Pole is tilted away. For the remaining part of the year, the situation is reversed. The Northern Hemisphere is certainly that half of the Earth which lies to the equator's north. In contrast, Southern Hemisphere lies to the south of the planet Earth's equator. Moreover, there are some continents have parts in both the hemispheres. Europe and North America lie completely in the northern hemisphere. Therefore near June 21st, the southern hemisphere is having its winter solstice because it "leans" away from the Sun. Advancing 90 days, the Earth is at the autumnal equinox on or about September 21st.

The 23.45° tilt between the equator and the orbital plane causes each Hemisphere to lean towards the sun for part of the year. So seasons are reversed between the two Hemispheres. Earth's tilted axis causes the seasons. Throughout the year, different parts of Earth receive the Sun's most direct rays. So, when the North Pole tilts toward the Sun, it's summer in the Northern Hemisphere. And when the South Pole tilts toward the Sun, its winter in the Northern Hemisphere. For the Southern Hemisphere, this is reversed. For both hemispheres, the earth is 90 degrees away from the sun around March 21 and then again around September 21. The seasons in the Northern Hemisphere are the opposite of those in the Southern Hemisphere. This means that in Argentina and Australia, winter begins in June. The winter solstice in the Southern Hemisphere is June 20 or 21, while the summer solstice, the longest day of the year, is December 21 or 22. Seasons in the Northern and Southern Hemispheres are opposite. When it is winter in the Northern Hemisphere, it's summer in the Southern Hemisphere. This is because Earth's axis is tilted in relation to its orbit around the Sun, known as axial tilt. This happens because, as the earth rotates around the sun, it is tilted or leans to one side. This causes one hemisphere to be closer to the sun while the opposite hemisphere faces away. The hemisphere facing the sun experiences summer while the hemisphere facing away from the sun experiences winter. Seasons are reversed in northern and southern hemispheres due to revolution as when the Earth comes near the Sun, the north pole experiences summer season and at the same time the south pole experiences winter season. The same goes when the south pole comes near the sun and vice - versa.