When Is Spring Equinox 2026. Spring equinox is the moment in which the sun enters aries. The 2025 spring equinox will occur on thursday, march 20, also marking the official start of the spring season.
Spring equinox 2026 (beginning of astronomical spring) on the day of the spring (march) equinox, the sun crosses the celestial equator, moving along the ecliptic. During march it is springtime in the northern hemisphere and march equinox is called vernal equinox and spring equinox while it is an autumn time in the southern hemisphere and march.