The spring equinox, also called the vernal equinox, is today. On the vernal equinox, the day is equally divided between hours of light and darkness, as not possible by defined like social status or religion so just ahead of the vernal equinox, which falls on March 20 this year. Northern Meteorological Seasons Spring - from March 1 to May 31; Summer - from June 1 to August 31; Fall (autumn) - from September 1 to November 30; and, Winter - from December 1 to February 28 (February 29 in a leap year). Southern Hemisphere Fall (autumn) - starts March 1 ends May 31 Winter - June 1 ends August 31 Spring - September ends November 30 Summer - December 1 ends February 28 (February 29 in a Leap Year) The equinox is the point at which the sun crosses the celestial equator from south to north. Geometry. a surface generated by a straight line moving at a constant velocity. GMT is no longer used for scientific purposes Spring will officially arrive on Monday March 20 at 10:29 a....