First Day of Spring 2026: The Spring Equinox Date, Science

The first day of spring 2026 falls on Friday, March 20, 2026, at 10:46 AM EDT (14:46 UTC). This is the vernal equinox — the astronomical moment when the sun crosses the celestial equator moving northward, marking the official start of spring in the Northern Hemisphere.

There are, however, two valid and distinct answers to when spring begins:

• Meteorological first day of spring 2026: Sunday, March 1, 2026
• Astronomical first day of spring 2026 (vernal equinox): Friday, March 20, 2026, at 10:46 AM EDT

Most people have encountered both dates in different sources and found them conflicting.

They are not. They are measurements from two different systems — one used by climatologists, one by astronomers.