Um, What Exactly Is the Spring Equinox and What Happens During It? (Asking for a Friend)

With the first day of spring taking place on Thursday, March 20, 2025, many of us know it means warmer weather is coming, but realistically, that's about it. Sure, we might know that it's called the spring equinox, but what does that really even mean? What is an equinox? What happens during an equinox? And who even decides which day is the first day of spring?

If you don't know the answers to these questions, don't feel embarrassed. You're in good company. Anyone can celebrate the fact that warmer days are coming, but it takes a bit of Googling to find out what the equinox really is all about. Luckily for you, we did the work for you.

Here's everything you need to know about the spring equinox: what it is, what it means, and why we celebrate it. 

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What Is the Spring Equinox?

The spring equinox is considered the start of spring in the Northern Hemisphere. Also known as the March equinox or vernal equinox, what it means exactly is that the sun crosses over the line of the equator. With the sun traveling north, it marks the beginning of spring.

According to Merriam-Webster, the word "equinox" comes from the Latin words aequi, meaning "equal" and nox, meaning "night." Together, "equinox" means "equal night," which is precisely what the spring equinox is. In all areas throughout the world, both the length of daytime and nighttime are exactly equal.

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When Is the Spring Equinox in 2025?

In 2025, the spring equinox—AKA the first day of spring—occurs on Thursday, March 20, 2025. So, who decides that? It's not a groundhog, and it's not a weatherman. This year, that's considered to be the first day of spring because it is the predicted date the sun will have crossed the equator—the first astronomical day of spring as per the Gregorian calendar.

Is Spring Equinox Always on the Same Day?

No. As Spectrum News reported, because it takes Earth 365.25 days to complete a rotation around the sun, that extra quarter of a day makes the spring equinox fluctuate from year to year. Next year, the spring equinox will occur on Friday, March 20, 2026.

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What Happens at the Spring Equinox?

As a result of the sun crossing the equator and being located more north in the sky, the Northern Hemisphere tilts more toward the sun. This creates more hours of daylight (think: Daylight Savings Time) and, as you can guess, warmer temperatures.

Now, it's almost the polar opposite for the Southern Hemisphere. There, the March equinox means the beginning of fall. As the Northern Hemisphere tilts more to the sun, the Southern Hemisphere tilts away from it. Cue autumn, colder temperatures and reduced hours of daylight for the Southern Hemisphere.

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Why Do People Celebrate Spring Equinox?

The spring equinox, or vernal equinox, has been celebrated for centuries. Historically, it has represented more than just the first day of spring or when the flowers begin to bloom. It has become a symbol for rebirth, fertility and new beginnings.

According to History.com, different cultures have celebrated the spring equinox for different reasons and in different ways. In ancient Maya, Mexico, people publicly gathered on the equinox to watch the sun make shadows against the Pyramid of Kukulcan or El Castillo. Today, the shadows are said to resemble a large, moving snake that descends down the pyramid throughout the afternoon as the sun moves.

In Japan, the spring equinox has been celebrated as a national holiday since 1948. Called Vernal Equinox Day or Shunbun no Hi, the celebrations include a one-weeklong festival, Haru no Higan. People celebrate by cleaning their homes (to signify a new start or rebirth), visiting their childhood homes and/or visiting and cleaning off the gravesites of their beloved departed.

What Is the Persian New Year?

Millions of people around the world celebrate the vernal equinox as a secular holiday known as Nowruz or the Iranian New Year or Persian New Year. The Persian New Year marks the first day of the month—known as Farvardin—on the Iranian calendar. Most often a 13-day celebration, people typically celebrate by jumping over a bonfire or lighting fireworks.

In the U.S., there is no one-fits-all ritual that Americans rely on to celebrate the spring equinox. It has become more about enjoying the weather, spending time in nature, planting flowers or gardening and even decorating Easter eggs to prepare for the upcoming holiday.

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