The Reason for the Seasons is because of the Earth's tilt and its orbit around the Sun. During the Summer Solstice, the Sun is directly over the Tropic of Cancer. The Northern Hemisphere is experiencing Summer while the Southern Hemisphere is experiencing Winter. During the Fall Equinox, the Sun is directly over the Equator. The Northern Hemisphere is experiencing Fall and the Southern Hemisphere is experiencing Spring. During the Winter Solstice, the Sun is directly over the Tropic of Capricorn. The Northern Hemisphere is experiencing Winter and the Southern Hemisphere is experiencing Summer. During the Spring Equinox, the Sun is directly over the Equator. The Northern Hemisphere is experiencing Spring and the Southern Hemisphere is experiencing Fall.