First Day Of Spring 2024 Events. On the equinoxes, the earth’s axis and orbit line up so both hemispheres get the same amount. Leap years are caused by earth's.
While it’s the first day of astronomical spring in north america, europe and asia, summer transitions to autumn in the southern hemisphere. Here are the equinox and solstice dates—plus, answers to common questions about the seasons of the year in north america.