CLEVELAND, Ohio -- The first day of spring 2015 will be on March 20, with winter officially ending at 6:45 p.m. that day. Summer 2015 will begin on June 21, fall on Sept. 23 and winter on Dec. 21. Source: National Weather Service. The first day of spring and fall each year marks the point when the length of days and nights are approximately equal everywhere on Earth, explained Mark Thompson, a meteorological technician for the National Weather Service in Cleveland.