When Does Spring Officially Start In 2024 Uk. This happens a few days before the official start of spring (vernal equinox) in the northern hemisphere. The first day of spring in the uk astronomically occurs on the vernal equinox, 20 march 2025.
That means every year spring begins on 1 march and lasts until 31 may. It’s officially the first day of spring, but why is it today and what is an ‘equinox’?