Spring Equinox 2024 Southern Hemisphere 2024. The september 22, 2024, equinox marks a significant astronomical event, heralding the beginning of fall in the northern hemisphere and the start of spring in the southern hemisphere. The start of astronomical spring, known as the vernal.

Spring equinox 2024 (beginning of astronomical spring) on the day of the spring (march) equinox, the sun crosses the celestial equator, moving along the ecliptic. When is the vernal equinox?