Spring Equinox 2025 Northern Hemisphere Time. In the southern hemisphere, it is known as the autumnal equinox and signals the beginning of fall. On the day of the autumn (september) equinox, the sun, moving along the ecliptic, crosses the celestial equator, moving from the northern hemisphere to the southern.
On the day of the winter (december) solstice, the sun passes through the southernmost point of the. In the southern hemisphere, spring starts on.