First Day of Fall 2025: What to Expect and When It Happens

WASHINGTON, D.C. — On Monday, September 22, 2025, the autumnal equinox will occur at 2:19 p.m. Eastern Daylight Time, marking the official start of fall in the Northern Hemisphere. At this moment, the sun will be directly above the equator, a phenomenon that also signifies the beginning of spring in the Southern Hemisphere.

The equinox happens twice a year, around March 20 and September 22, when day and night lengths are nearly equal worldwide. While the term ‘equinox’ comes from the Latin words for ‘equal night,’ this is a simplified explanation. Atmospheric refraction can extend daylight slightly, resulting in days lasting longer than 12 hours.

In Atlanta, for instance, sunrise on September 22, 2025, will occur at 7:25 a.m. and sunset will be at 7:33 p.m., allowing for 12 hours and 8 minutes of daylight. Not until September 26 will day and night be truly equal in many locations.

As the sun approaches the horizon, it appears distorted due to atmospheric effects. During the equinox, the sun will seem to skim along the horizon, while in reality, it will be just below it. The optical illusion can lead to misconceptions about daylight duration during this time.

Myths persist about the Arctic experiencing six months of continuous daylight or darkness. However, even at the North Pole, darkness does not occur immediately; civil twilight lasts until October 8, meaning some light remains even when the sun is below the horizon.

Joe Rao, an instructor at New York’s Hayden Planetarium and a well-known astronomy writer, highlights the significance of the equinox. He notes that while the equinox indicates the end of summer according to astronomers, meteorologists mark summer’s end on August 31.

As foliage turns and pumpkin spice lattes return, preparations for Halloween and Thanksgiving begin. This year, daylight saving time will end on November 2, allowing for more daylight in winter mornings, transitioning the country into a new seasonal rhythm.

The autumn equinox is not just about the changing seasons but also about the scientific alignment of Earth and the sun, a celestial dance that dictates the movement of shadows and light throughout the year.