When Is The First Day Of Spring 2025 Usa Dates. Vernal / spring equinox 2025 the spring or vernal equinox marks the astronomical first day of spring. Spring begins with the vernal equinox, thursday, march 20, 2025, 5:01 a.m.

When do the four seasons start in 2025—for spring, summer, fall, and winter? See first day of spring 2025.