Autumn for the year 2010 starts on Wednesday, September 22nd for the Northern Hemisphere and on Sunday, March 21st for the Southern Hemisphere. Wednesday, September 22nd is day number 265 of the 2010 calendar year with -9 years, -4 months, -26 days until the start of Autumn 2010 in Northern Hemisphere (Denver, USA). Sunday, March 21st is day number 80 of the 2010 calendar year with -9 years, -10 months, -28 days until the start of Autumn 2010 in Southern Hemisphere (Sydney, Australia). More information on Autumn. (Latitude, Longitude and Sun location over Equator)|Name(s):||Autumn, Fall, Autumn Equinox||When:||September 21st thru 24th (N.Hemisphere), March 20th thru 23rd (S. Hemishpere)|