First Day Of Spring 2025. The first day of spring in the uk astronomically occurs on the vernal equinox, 20 march 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.
There are four astronomical seasons on earth, defined by the movement of the sun in the sky. Seasons divide the year into four distinct periods of time named spring, summer, autumn/fall, and winter.