Autumn Equinox Southern Hemisphere 2024 Time. In the northern hemisphere, these are known as the spring, or vernal, equinox and the fall, or autumnal, equinox. Equinoxes happen when the earth’s hemispheres aren’t tilted towards or away from the sun.
As a result, the sun stays right above the equator, giving both hemispheres almost the same. Normally, the autumn equinox falls between 22 and 24 september, and this year the equinox occurs on 22 september at 13:44 bst.