Spring officially begins today (March 20) with the vernal equinox, bringing longer days and warmer temperatures to the Northern Hemisphere.

An illustration of the sun crossing the celestial equator to mark the March equinox on March 20, 2025. (Image credit: Chris Vaughan/Starry Night)

The vernal equinox signals the astronomical start of spring in the Northern Hemisphere, with the sun crossing above Earth's equator, moving from south to north, at 5:01 a.m. EST (0901 GMT) on March 20. This means that after months of being pointed away from the sun during the winter, the Northern Hemisphere will now begin pointing toward the sun, according to In-the-Sky.org.

As the Northern Hemisphere welcomes spring today, the Southern Hemisphere greets the first day of autumn.

The word equinox is derived from the Latin words "aequus" (equal) and "nox" (night). There are two equinoxes in the year — vernal in the spring and autumnal in the fall — when daylight and night are roughly equal due to the Earth's tilt and the planet's position in its orbit around the sun.