Thursday is the first day of spring, or the vernal equinox, in the Northern Hemisphere. During an equinox, the center of the sun is on the same plane as the equator. After the vernal equinox in March, the Northern Hemisphere tilts toward the sun until the June solstice, when the sun begins to migrate back south.

The spring equinox marks the start of astronomical spring. The date is determined by the Earth's tilt on its axis as it travels around the Sun. At the equinox, the Earth's axis is tilted neither towards nor away from the Sun, making day and night nearly equal in length. The equinox happens twice a year - in March and in September.

No. As Spectrum News reported, because it takes Earth 365.25 days to complete a rotation around the sun, that extra quarter of a day makes the spring equinox fluctuate from year to year. Next year, the spring equinox will occur on Friday, March 20, 2026. Related: 27 Spring Recipes To Welcome Warmer Days Because 'We Can't' With Winter Anymore

The spring equinox is a "vital part" of the astronomical calendar as it signals the transition from winter to spring

It’s far too early to try to fry an egg on the sidewalk, but according to weather lore, the spring equinox is an ideal time to try to balance an egg!