We have four seasons because the Earth doesn’t sit up straight: It’s tilted on its axis. As it orbits the sun, the planet’s slight slouch exposes more or less of the Northern and Southern Hemispheres to the sun, depending on the time of year. When the South Pole is pointed toward the sun, Australia and other countries south of the Equator receive more direct sun exposure, resulting in warm summer temperatures. At the same time, the North Pole is pointed away from the sun, reducing sun exposure and making for chilly winter temperatures. The farther you are from the Equator, the greater this seasonal effect.
Picture Credit : Google