Astronomical autumn to start at about 11:20 a.m. on Wednesday in Bulgaria when the September equinox will occur, the National Institute of Meteorology and Hydrology with the Bulgarian Academy of Science announced. Autumn is one of the four temperate seasons.

It begins astronomically with the autumnal equinox, which is seen around September 23 in the Northern Hemisphere and around March 21 in the Southern Hemisphere.

According to meteorology, the autumnal months are September, October, and November in the Northern Hemisphere as well as March, April, and May in the Southern Hemisphere.