First Day of Seasons: 2013

When Do Fall, Winter, Spring, and Summer Begin?

See chart below for exact dates and times for the first day of each season in 2013 —namely, the fall or autumnal equinox, winter solstice, spring or vernal equinox, and summer solstice.

Why do the seasons change? The four seasons are determined by shifting sunlight (not heat!)—which is determined by how our planet orbits the Sun and the tilt of its axis.

• On the first day of fall —the autumnal equinox —day and night are each about 12 hours long (with the actual time of equal day and night, in the Northern Hemisphere, occurring a few days after the autumnal equinox). The Sun crosses the celestial equator going southward; it rises exactly due east and sets exactly due west. See our First Day of Fall page !


• The start of winter—the winter solstice —is the darkest day of the year when the Sun reaches its most southern point in the sky at local noon. After this date, the days start getting "longer," i.e., the amount of daylight begins to increase.  See our First Day of Winter page !


• On the first day of spring—the vernal equinox —day and night are each approximately 12 hours long (with the actual time of equal day and night, in the Northern Hemisphere, occurring a few days before the vernal equinox). The Sun crosses the celestial equator going northward; it rises exactly due east and sets exactly due west. See our First Day of Spring page !


• On the  first day of summer—the summer solstice —we enjoy the most daylight of the calendar year. The Sun reaches its most northern point in the sky at local noon. After this date, the days start getting "shorter," i.e., the length of daylight starts to decrease.  See our First Day of Summer page !
  

  
  Credit: NASA

  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  

  Seasons of 2013:
  SPRING EQUINOX	March 20, 7:02 A.M. EDT
  SUMMER SOLSTICE	June 21, 1:04 A.M. EDT
  FALL EQUINOX	September 22, 4:44 P.M. EDT
  WINTER SOLSTICE	December 21, 12:11 P.M. EST

  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  

  Seasons of 2014:
  SPRING EQUINOX	March 20, 12:57 P.M. EDT
  SUMMER SOLSTICE	June 21, 6:51 A.M. EDT
  FALL EQUINOX	September 22, 10:29 P.M. EDT
  WINTER SOLSTICE	December 21, 6:03 P.M. EST

  
  


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