Autumn Equinox 2025 Southern Hemisphere. When is the march equinox 2025.on the day of the spring (march) equinox, the sun crosses the celestial equator, moving along the ecliptic. In 2025, the first day of autumn in australia (southern hemisphere) will occur on tuesday, march 20 at sharp 02:07 pm australian eastern daylight time (aedt).
A solstice is the day when the sun is at its highest or. 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.