The season of the year which occurs as the sun approaches the winter solstice, and characterized by decreasing temperatures in the mid-latitudes. Customarily, this refers to the months of September, October, and November in the North Hemisphere and the months of March, April, and May in the Southern Hemisphere. Astronomically, this is the period between the autumnal equinox and the winter solstice.
AUTUMN
Meaning of AUTUMN in English
Weather and meteorology English vocabulary. Английский словарь погоды и метеорологии . 2012