During an equinox, the Earth's axis isn't tilted toward or away from the sun, so the sun shines directly over the equator, according to the NWS.
What could the weather hold for spring in the U.S.?
In 2020, the spring equinox happens at 11:50 p.m.
Spring is officially coming early this year, thanks to leap year and other solar quirks that will make the season's arrival fall on March 19 for the first time throughout the US since 1896. For the US the 2020 equinox falls on March 19, making it the earliest since 1896.
Which hemisphere you're in at the time determines exactly which kind of equinox you're experiencing.
The longer answer involves leap years.
The Earth is tilted on its axis.
The sun will also appear to rise exactly east and set exactly west today, according to Space.com.
The extra day every fourth February STILL leaves us slightly out of whack with the solar year.
It turns out you actually get a little more daylight than darkness on the equinox, depending where you are on the planet. But remember, the actual length is closer to 365.24 days. That's because the Earth's 574,395,530-mile annual orbit of the sun really takes 365.2422 days.
The equinox gets later each year and then "jumps back" on the next leap year.
All those little rounding errors add up over time. But there's an exception to that: The centurial years that are exactly divisible by 400 are leap years.
The solstice also is the shortest day of the year in the Southern Hemisphere. Thursday is the vernal or spring equinox in the Northern Hemisphere.
But all that time, the equinox was slowly getting earlier by about 45 minutes every four years.
Again: 1900 wasn't. But 2000 WAS. The last time the equinox fell on March 19, was way back in 1896!
Will spring always be early?
2004's equinox is of half an hour earlier than 2000's. According to Space.com it's the earliest in 124 years. Accuweather claims that designation is from March 1 through the end of May. "We all sort of think that the universe was made for us", she says.
The Jefferson Memorial is framed by cherry blossom trees in full bloom along the Tidal Basin in Washington. "The only thing that's going to help the loneliness is each other".