March Equinox (Beginning of Spring)

March Equinox in Boston, Massachusetts

There are two equinoxes each year: one in March and one in September.

In March, the Sun crosses the celestial equator—an imaginary line in the sky above Earth’s equator—from south to north.

The March and September equinoxes mark the beginning of the spring and autumn seasons on Earth, according to one definition. The equinox in March is the start of spring in the Northern Hemisphere and the beginning of autumn south of the equator. Learn more here.