Autumn Equinox 2024 Australia. Autumn officially graces australia on march 21st, marking the autumnal equinox. Autumn equinox 2024 (beginning of astronomical autumn) on the day of the autumn (september) equinox, the sun, moving along the ecliptic, crosses the celestial equator, moving from the.

Australians are now facing six months of longer nights after yesterday marked the southern hemisphere’s autumn equinox. The sun crosses over the equator again in late march, and days and nights are again the same length.