Spring Equinox 2025 Usa Schedule. The spring equinox 2025 is a significant astronomical event that marks the beginning of spring in the northern hemisphere and autumn in the southern hemisphere. On this date, the day is equal in length to the night.

On the evening of monday, jan. The first day of spring (march equinox or vernal equinox) is when the sun shines directly on the celestial equator passing from south to north and the length of.