 Although there’s nothing official about it, it’s traditional to say the March or vernal equinox signals the beginning of spring in the Northern Hemisphere and autumn in the Southern Hemisphere. Video: 
 
 March Equinox 2016 Dates and Times 
 
 This year, the vernal equinox arrives on Saturday, March 19 or Sunday, March 20, 2016, depending on your time zone: 
 
 Saturday, March 19, 2016 at 9:30 PM PDT 
 
 Saturday, March 19, 2016 at 10:30 PM MDT 
 
 Saturday, March 19, 2016 at 11:30 PM CDT 
 
 Sunday, March 20, 2016 at 12:30 AM EDT 
 
 Sunday, March 20, 2016 at 04:30 UTC (Universal Time) 
 
 When Does Spring Begin? In the Northern Hemisphere now, we’re enjoying earlier sunrises, later sunsets, softer winds, sprouting plants. For all of us on this March 2019 equinox, the full moon will come less than 4 hours after the equinox: on March 21 at 1:43 UTC. At the Vernal Equinox, the Sun crosses the celestial equator on its way north along the ecliptic. The Earth-in-space view is that, because Earth doesn’t orbit upright, but is instead tilted on its axis by 23 1/2 degrees, Earth’s northern and southern hemispheres trade places in receiving the sun’s light and warmth most directly, as Earth orbits the sun. On the equinox, Earth’s two hemispheres are receiving the Sun’s rays about equally because the tilt of the Earth is zero relative to the Sun, which means that Earth’s axis neither points toward nor away from the Sun. The name equinox comes from Latin words which mean “equal night”—aequus (equal) and nox (night). Scientific explanation aside, our ancestors were more connected to the Sun than we are today. If the Sun were to shrink to a starlike point and we lived in a world without air, the spring and fall equinoxes would truly have ‘equal nights.’ 
 
 Read more about why day and night are NOT quite equal. Here’s another equinox truism. Is this true? First, daytime begins the moment any part of the Sun is over the horizon, and it is not over until the last part of the Sun has set. March Equinox 2016 Show 
 
 The video (below) is a replay of the live broadcast from Saturday, March 19. The captured year ends again with the September equinox, concluding another of billions of trips the Earth has taken — and will take — around the sun. Signs of the Equinox in Nature 
 
 The vernal equinox signals the beginning of nature’s renewal in the Northern Hemisphere! Forget about the weather for a moment, and think only about the daylight. Notice the arc of the Sun across the sky as it shifts toward the north. Responding to the change in daylight, birds and butterflies are migrating back northward, too, along with the path of the sun. (MORE: The Science Behind the First Day of Spring) 
 
 If you needed any more reminders of how changeable the weather can be this time of year, this is your exhibit A. The whole Earth smiles, thy coming to greet. It’s an event that happens on our sky’s dome – and a seasonal marker in Earth’s orbit around the sun!
– Residents of the Northeast are expecting a snowstorm this weekend, but they can warm themselves with one thought: It's spring. The new season officially arrives at 12:30am EDT on Sunday, March 20, notes the Old Farmer's Almanac. And as EarthSky points out, this happens to be the earliest arrival of spring since 1896—the result of a fluke in the calendar. "In a nutshell, this earliest spring is happening because the tropical year, as measured between successive March equinoxes, doesn't have an even number of days (365.242 days)," explains the post. And so leap years (366 days) vs. non-leap years (365 days) adjust its timing. And Pope Gregory XIII threw a wrench into things: In 1582 he decreed that leap year not fall on centennial years, unless that year was divisible by four—so 2000 was considered a leap year, but not 1900. That "causes the March equinox to arrive roughly three-quarters of a day earlier in the 21st century than at corresponding years in the 20th century," explains the post. Every four years, the March equinox will shift earlier, ultimately bringing us to the earliest one of the 21st century: 10:03am March 19, 2096. Come 2100, where there is also no leap year, the March equinox times will be pushed forward, and will once again occur on March 21 in 2102. As for that potential nor'easter, it looks like Sunday will be the day for snow, but much remains iffy about the forecast, reports Weather.com.