The Arrival of the Spring Equinox
The spring equinox arrives on Thursday, marking the start of the spring season for the Northern Hemisphere and the fall in the Southern Hemisphere. On the equator, the sun will be directly overhead at noon. Equinoxes are the only time when both the north and south poles are lit by sunshine at the same time.
Celebrations Around the World
The events have been marked and celebrated around the world for centuries. Nowruz, the Iranian New Year, is based on the spring equinox, for example. And at the Mayan site Chichen Itza in Mexico, people gather during the equinox to watch the sun create a shadow pattern that resembles a serpent descending a building called El Castillo.
Spring is almost here — officially, at least.
Understanding the Equinox
As the Earth travels around the sun, it does so at an angle. For most of the year, the Earth’s axis is tilted either toward or away from the sun. That means the sun’s warmth and light fall unequally on the northern and southern halves of the planet.
What is the Equinox?
During the equinox, the Earth’s axis and its orbit line up so that both hemispheres get an equal amount of sunlight. The word equinox comes from two Latin words meaning equal and night. That’s because on the equinox, day and night last almost the same amount of time — though one may get a few extra minutes, depending on where you are on the planet.
What is the Solstice?
The solstices mark the times during the year when the Earth is at its most extreme tilt toward or away from the sun. This means the hemispheres are getting very different amounts of sunlight — and days and nights are at their most unequal. During the Northern Hemisphere’s summer solstice, the upper half of the earth is tilted in toward the sun, creating the longest day and shortest night of the year. This solstice falls between June 20 and 22.
This image provided by NOAA on March 19, 2025 shows Earth. (NOAA via AP)
Meanwhile, at the winter solstice, the Northern Hemisphere is leaning away from the sun — leading to the shortest day and longest night of the year. The winter solstice falls between December 20 and 23.
Meteorological vs. Astronomical Seasons
These are just two different ways to carve up the year. While astronomical seasons depend on how the Earth moves around the sun, meteorological seasons are defined by the weather. They break down the year into three-month seasons based on annual temperature cycles. By that calendar, spring starts on March 1, summer on June 1, fall on Sept. 1 and winter on Dec. 1.
Conclusion
The spring equinox is a significant event that marks the beginning of the spring season in the Northern Hemisphere and the fall season in the Southern Hemisphere. It is a time of equal daylight and darkness, and it has been celebrated by various cultures around the world for centuries. Understanding the equinox and the solstices can help us appreciate the changing seasons and the Earth’s orbit around the sun.
FAQs
Q: What is the spring equinox?
A: The spring equinox is the moment when the Earth’s axis and its orbit line up, resulting in equal amounts of sunlight in both hemispheres.
Q: What is the difference between the equinox and the solstice?
A: The equinox occurs when the Earth’s axis is perpendicular to the sun’s rays, resulting in equal daylight and darkness, while the solstice occurs when the Earth’s axis is tilted towards or away from the sun, resulting in the longest or shortest day of the year.
Q: How do meteorological seasons differ from astronomical seasons?
A: Meteorological seasons are defined by temperature cycles, while astronomical seasons are based on the Earth’s orbit around the sun.
Originally Published: March 19, 2025 at 12:42 PM EDT
