Vernal Equinox

The vernal equinox (or spring equinox) marks the beginning of astronomical spring. It occurs during the month of March in the Northern Hemisphere, and during September in the Southern Hemisphere. In Chinese culture the vernal equinox marks the middle of spring.

At the same moment that the vernal equinox occurs in one hemisphere, it is the time of the autumnal equinox in the other hemisphere.