Autumn - one of four seasons, between summer and the winter. The autumn - a transitional season when reduction of light day is appreciable, and gradually goes down ambient temperature.
Consists of three months: in the Northern hemisphere - September, October and November, in South - March, April and May. By amount arriving on the earth from the Sun of energy of an equinox should be the middle of the corresponding seasons. But the delay in temperature change (caused by physical properties of water and the earth) detains climatic seasons of rather astronomical. The temperature delay changes depending on a concrete place therefore in one cultures the autumn equinox is regarded as the middle of autumn, and in others - as an early autumn.
Beautiful images of autumn waiting for you, look at this amazing season.