This ends with the winter solstice, after which days start to grow longer once again. In the Southern Hemisphere, it’s the reverse.Īfter the autumnal equinox, days become shorter than nights as the Sun continues to rise later and nightfall arrives earlier.
What Is an Equinox?ĭuring an equinox, the Sun crosses what we call the “celestial equator”-an imaginary extension of Earth’s equator line into space. The equinox occurs precisely when the Sun’s center passes through this line.įor those in the Northern Hemisphere, when the Sun crosses the equator going from north to south, this marks the autumnal equinox when it crosses from south to north, this marks the vernal equinox. In the Northern Hemisphere, the autumnal equinox occurs in September in the Southern Hemisphere, it occurs in March. The autumnal equinox is an astronomical event that marks the start of autumn (or “fall”).
The First Day of Winter: Winter Solstice 2023
