Autumn or Fall is one of the four temperate seasons. Autumn marks the transition from summer into winter, in September (Northern Hemisphere) or March (Southern Hemisphere) when the arrival of night becomes noticeably earlier.
In North America, autumn is usually considered to start with the September equinox. In traditional East Asian solar term, autumn starts on or around 8 August and ends on about 7 November. In Ireland, the autumn months are September, October and November.In Australia, autumn officially begins on 1 March and ends 31 May.