The Equinox is when the Sun's rays are directly over the equator. That happens twice a year when day and night are almost equal in lengths. The 2020 September Equinox happens on Tuesday, Sept. 22, at 13 31 UTC. Although the equinox happens at the same moment worldwide, your clock time will depend on your time zone. For time zones in the continental U.S., this equinox comes early in the morning on September 22 (9 31 a.m. EDT, 8 31 a.m. CDT, 7 31 a.m. MDT and 6 31 a.m. PDT). Why does Earth have seasons? The Earth has seasons not because it gets closer to the Sun in the summer and then further away from the Sun in the winter. It does get a little closer and further from the Sun in its orbit, but what really causes the seasons is the fact that the Earth is tilted. Winter Solstice High summer for the Southern Hemisphere, Winter for the Northern Hemisphere. What happens in Spring and Fall? Equinox: The time when the Sun crosses the plane of the Earth's equator, making equal length of night and day. Enjoy the September Equinox – a seasonal signpost in Earth’s orbit around the Sun! Stay Tuned!