Autumn, or fall, is the season between summer and winter, whenplants and animals transition from warmer, longer days (summer) tocooler, shorter days (winter). The average dail
…y temperaturetypically goes downward as the season progresses. Some plants losetheir leaves, and some animals migrate southward. The position of the Earth in its orbit around the Sun causes theseasons as we know it. Because of the Earth's axial tilt, 23.4degrees, the northern hemisphere receives more direct sunlight forhalf of the year and the southern hemisphere receives more for theother half. The seasons begin and end, astronomically speaking, on theequinoxes and solstices. In the Northern Hemisphere, autumn begins at the (fall, autumnal)equinox around 22 September and ends at the (winter) solsticearound 21 December. In the Southern Hemisphere, where the seasons are reversed, autumnbegins around March 20 and ends at the solstice on June 21. ( Full Answer )