Fall is here, at least on the calendar, even though the weather still feels like summer in a lot of places. The autumn equinox is what scientists point to as the true start of the fall season. This year, the first day of fall lands on Monday, September 22, at 2:19 p.m. Eastern for the Northern Hemisphere as per NBC. That is when day and night line up to be almost equal across the globe, about 12 hours each. It is a shift that people have tracked for centuries as the sign that summer is ending.
Meteorological fall is different
For meteorologists, though, fall already started earlier. They count the seasons by temperature cycles, not by the sun’s path. So for them, autumn began on September 1. That is why you may hear reports calling it fall long before the actual equinox hits.
Daylight saving time
The arrival of fall also sets up the countdown to the clock change. In 2025, daylight saving time ends on November 2 at 2 a.m. when clocks “fall back” an hour. Most people like the extra hour of sleep, but it means sunsets come much earlier. By November, darkness will fall before 7 p.m., something that catches people off guard each year. The Spring does not arrive until March 2026.
What autumn equinox really means
The autumn equinox happens because of the Earth’s tilt. Our planet leans at about 23.5 degrees while moving around the sun. On this date, the tilt is not pointing toward or away, which lets the sunlight hit both hemispheres evenly. That creates the balance of daylight and night. From here on, days in the Northern Hemisphere grow shorter, nights grow longer, and the march to winter begins.
{{/usCountry}}The autumn equinox happens because of the Earth’s tilt. Our planet leans at about 23.5 degrees while moving around the sun. On this date, the tilt is not pointing toward or away, which lets the sunlight hit both hemispheres evenly. That creates the balance of daylight and night. From here on, days in the Northern Hemisphere grow shorter, nights grow longer, and the march to winter begins.
{{/usCountry}}Winter solstice ahead
The next big marker will be the winter solstice on Sunday, December 21, 2025. That will be the shortest day of the year, with only nine hours and 17 minutes of daylight. It is also considered a turning point since after that, the days slowly get longer again. So even if the heat lingers, fall has officially started, bringing shorter days, cooler nights, and the first signs of change.
FAQs:
When is the first day of fall 2025?
The first day of fall is Monday, September 22, 2025, at 2:19 p.m. Eastern Time.
What is the autumnal equinox?
It is the astronomical start of fall in the Northern Hemisphere when day and night are nearly equal.
How does fall differ for meteorologists?
Meteorologists mark fall from September 1 based on temperature cycles, not the equinox.
When do clocks fall back in 2025?
Daylight saving ends on Sunday, November 2, 2025, when clocks move back one hour at 2 a.m.