Spring Solstice 2025. Spring equinox 2025 (beginning of astronomical spring) on the day of the spring (march) equinox, the sun crosses the celestial equator, moving along the ecliptic. The vernal equinox marks the beginning of astronomical spring, while the autumnal equinox marks the beginning of autumn.
The winter solstice, the official start of winter, will occur at 4:21 p.m. When is the first day of spring 2025, and what is the spring equinox?