During an equinox, places around the globe experience nearly equal amounts of daytime and nighttime. The second occurrence this year happens on Sunday.

On Sept. 22, the fall equinox formally heralds in autumn and marks the end of summer in the Northern Hemisphere.

Today marks the autumnal equinox, or the first day of astronomical fall. Have you ever wondered why it occurs on a different day and at a different time each year? Let’s break it down! Let’s start with the basics.

The first day of fall is on Sunday, Sept. 22, 2024, in the Northern Hemisphere. These are just two different ways to carve up the year. Meteorological seasons are defined by the weather. They break down the year into three-month seasons based on annual temperature cycles.

Even though pumpkin spice-flavored everything made a premature return to menus and store shelves everywhere, the first day of fall is actually this Sunday. Sept. 22, marks the first day of the autumnal equinox in the Northern Hemisphere,