Spring begins with the vernal equinox at 7:02 A.M. (EDT) on March 20, 2013 in the Northern Hemisphere.
The Vernal Equinox
Ah, spring! This season brings increasing daylight, warming temperatures, and the rebirth of flora and fauna.
The word equinox is derived from the Latin words meaning “equal night.” Days and nights are approximately equal everywhere and the Sunrises and sets due east and west.