When Is Spring Solstice 2024 Usa. The reason the first day of spring was march 19 was because 2024 is a leap year. Autumnal/fall equinox north of the equator is mirrored south of the equator by the spring equinox.
On the equinoxes, the earth’s axis and orbit line up so both hemispheres get the same amount. On this date, the day is equal.