First Day of Spring 2025: The Spring Equinox

When Is the First Day of Spring 2025?

In 2025, the March equinox happens on March 20 at 5:01 A.M. EDT. This falls on a Thursday and is the astronomical beginning of the spring season in the Northern Hemisphere and the autumn season in the Southern Hemisphere.

If you thought that the spring equinox only ever occurred on March 21, you may be dating yourself. The civil calendar date of the equinox continues to shift every year. Find out why.

What Is the Spring Equinox?

In the Northern Hemisphere, the spring equinox (also called the March equinox or vernal equinox across the globe) occurs when 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 Earth’s equator. Imagine standing on the equator; the Sun would pass directly overhead on its way north. 

On the March equinox, the Northern Hemisphere and Southern Hemisphere receive roughly equal amounts of sunlight; neither hemisphere is tilted more toward or away from the Sun than the other.

Although in most locations (the North Pole and the equator being exceptions), the amount of daylight had been increasing each day after the winter solstice—and 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), when the longest period of daylight occurs.

→See your personalized Sunrise and Sunset calculator.

Here’s an interesting fact: Equinoxes are the only two times yearly that the Sun rises due east and sets due west for all of us on Earth! While the Sun passes overhead, the tilt of Earth is zero relative to the Sun, which means that Earth’s axis neither points toward nor away from the Sun. (Note, however, that Earth never orbits upright but is always tilted on its axis by about 23.5 degrees.)

Read more about the reason for the seasons.

What Does “Equinox” Mean?

The word equinox comes from the Latin words for “equal night”—aequus (equal) and nox (night). On the equinox, the length of day and night is nearly equal in all parts of the world. 

Spring Equinox FAQs

Q: Does Spring Begin on March 1 or on the Equinox?

A: 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. The equinox happens at the exact moment worldwide, although 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 hasn’t been a March 21 equinox in mainland United States 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. Meteorological seasons more closely follow the Gregorian calendar since 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.

Q: Are Day and Night Equal on the Equinox?

A: Quite close! In reality, day and night are not exactly equal on the equinox. Daytime begins the moment any part of the Sun appears over the horizon and is not finished until the last part of the Sun disappears below the horizon. 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 about more fun facts in the Almanac Astronomer’s post, “Vernal Equinox Oddities.”

Q: According to folklore, you can stand a raw egg on its end on the equinox. Is this true?

A: This egg folklore became popular in 1945 following a LIFE article about the spring practice. “The origins of this myth are attributed to stories that the ancient Chinese would create displays of eggs standing on end during the first day of spring,” according to John Millis, assistant professor of physics and astronomy at Anderson University in South Carolina. “The ancient Chinese celebrated the first day of spring about six weeks earlier than the equinox”—not just on the equinox itself.

As with most folklore, it’s only partly true. You should be able to balance an egg on its end on the equinox, but it’s possible to balance an egg on other days, too!

Folklore or not, this egg trick sounded like fun to us. One spring, a few minutes before the vernal equinox, several Almanac editors tried this trick. For a full workday, 17 out of 24 eggs stood on end. Three days later, we tried this trick again and found similar results. Perhaps three days after the equinox was still too near. Perhaps the equinox has nothing to do with it. Perhaps we just don’t like to take ourselves too seriously!

Try this yourself and let us know what happens. (Tip: You’ll probably have better luck balancing an egg if you try it on a rough surface—or use an egg that has a bumpy end.)

Q: Which day has the most Sunlight in North America?

A:  The summer—or “June”—solstice is called the “longest” day of the year! The date of the longest day actually varies from June 20 to June 22, depending on the year and the local time zone. By “longest day,” we mean the day with the most daylight (versus darkness). See our Summer Solstice page.

Some Ideas on How to Celebrate Spring!

The vernal equinox signals new beginnings and nature’s renewal in the Northern Hemisphere! Many cultures celebrate spring festivals, such as Easter and Passover.