First Day of Spring 2021: The Spring Equinox

_Elsa_

On the other side of town, Tiffi is bored out of her mind. She cannot go for a walk because the snow must be knee high already. She is really not in the mood to shovel either. Time to do some googling. What should she search for? Aha! She decides that she will help Elsa get some season information for the new story. 

‘Celebrate the Vernal Equinox and the Start of Spring! In 2021, the spring equinox occurs on Saturday, March 20. This event marks the astronomical first day of spring in the Northern Hemisphere. 

The March Equinox - In the Northern Hemisphere, the March equinox (aka spring equinox or vernal equinox) occurs when the Sun crosses the equator line, heading north in the sky. This event marks the start of spring in the northern half of the globe. After this date, the Northern Hemisphere begins to be tilted more toward the Sun, resulting in increasing daylight hours and warming temperatures. 

When Is the First Day of Spring? - In 2021, the March equinox happens on Saturday, March 20, at 5:37 A.M. EDT. In the Northern Hemisphere, this date marks the start of the spring season.

What Happens on the March Equinox? - On the March equinox, the Sun crosses the celestial equator going south to north. It’s called the “celestial equator” because it’s an imaginary line in the sky above the Earth’s equator.

If you were standing on the equator, the Sun would pass directly overhead on its way north.  Equinoxes are the only two times a year that the Sun rises due east and sets due west for all of us on Earth!

While the Sun passes overhead, 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. (Note, however, that the Earth never orbits upright, but is always tilted on its axis by about 23.5 degrees.)

After the spring equinox, the Northern Hemisphere tilts toward the Sun. Although in most locations (the North Pole and Equator being exceptions) the amount of daylight had been increasing each day after the winter solstice, after the spring equinox, many places will experience more daylight than darkness in each 24-hour day. The amount of daylight each day will continue to increase until the summer solstice in June, in which the longest period of daylight occurs.

Does Spring Begin on March 1 or on the Equinox? - Well, both. The answer depends on your definition of “spring.” Both dates are accurate; they’re just from different perspectives. We’ll explain …

Astronomically speaking, the first day of spring is marked by the spring equinox, which falls on March 19, 20, or 21 every year. The equinox happens at the same moment worldwide, though our clock times reflect a different time zone. And, as mentioned above, this date only signals spring’s beginning in the Northern Hemisphere; it announces fall’s arrival in the Southern Hemisphere.

Interestingly, due to time zone differences, there isn’t a March 21 equinox in mainland U.S. during the entire 21st century! We won’t see a March 21 equinox again until 2101.

Meteorologically speaking, the official first day of spring is March 1 (and the last is May 31). Weather scientists divide the year into quarters to make it easier to compare seasonal and monthly statistics from one year to the next. The meteorological seasons are based on annual temperature cycles rather than on the position of Earth in relation to the Sun, and they more closely follow the Gregorian calendar. Using the dates of the astronomical equinoxes and solstices for the seasons would present a statistical problem, as these dates can vary slightly each year.’ (Source)

Tiffi decides to give Elsa a call to let her know that she’s looking for seasons articles for her.

Elsa tells her to keep looking. Maybe she can make her a co-author again!

Let’s continue - What's the Difference Between a Solstice and an Equinox?

Start at the beginning – The year that spring forgot