Articles About Equinox (16)

March Equinox

At the March equinox, the Sun crosses the equator from south to north. Explanation and 2025 equinox date.

September Equinox

The Sun shines directly on the Equator on the September equinox and the length of day and night is nearly equal, but not quite.

When Does Spring Start?

The first day of spring is at the vernal equinox, when day and night are equal. Find out the exact time and date.

When Does Fall Start?

North of the equator, fall begins in September. Find out the exact dates for both hemispheres.

The Earth in space, as seen by the crew of Apollo 11.

Equinoxes and Solstices

Equinoxes and solstices are a result of Earth’s tilt and its orbit around the Sun.

Illustration of night sky with stars and a crescent moon.

Astro Events 2025

When, where, and how to see things happening in the sky and space.

A tree changing through the four seasons.

What Causes Seasons on Earth?

Seasons change because Earth's rotational axis tilts away or towards the Sun during the course of a year.

Diagram showing the distance between the Sun and Earth at different times of the year (perihelion and aphelion).

Earth's Perihelion

Earth's closest approach to the Sun is two weeks after the December solstice is a coincidence and has no special significance.

Sun setting in the background with cloudy sky and trees in the foreground.

Equinox: Equal Day & Night?

Equinoxes don't have exactly 12 hours of day and night all over the world, like many believe. Such days, called equilux, do occur, but depend on your location.

Vector illustration of thick book and a pencil

Astronomical Glossary - Terms & Definitions

What do astronomers really mean when they use those technical terms?

Illustration showing Earth's axis drawn as a red line.

Earth Is Tilted

When an object the size of Mars crashed into the newly formed planet Earth around 4.5 billion years ago, it knocked it over and left it tilted at an angle.

A pathway in a park during fall (autumn).

10 Facts about the September Equinox

10 things you may not know about the September equinox.

10 Facts about the March Equinox

On this date, day and night are of almost equal duration around the world.

June Solstice Traditions

In many Northern Hemisphere cultures, the June solstice is associated with holidays, feasts and celebrations.

September Equinox Customs

Folklore, customs, traditions and holidays surrounding the September equinox.

March Equinox Customs

Learn more about the customs, traditions and events surrounding the March equinox.