Seasons:Fall / Autumn : Fall, also known as Autumn is one of the four temperate seasons*. *Some parts of the world consider rains / monsoon as a fifth season. Fall marks the transition from summer into winter. Fall starts around September 15th, and ends about December 20th. Fall commemorates the celebrations of the harvest. In the USA, an important festival celebrated in mid-fall is Thanksgiving. Fall is also associated with the Halloween season. Nature also highlights changes in the season. In fall the color in deciduous trees changes. Colored fall foliage is most famous in Canada and USA and in Eastern Asia, which includes China, Korea, and Japan. Eastern Canada and the New England region of the United States are famous for the brilliance of their fall foliage.