The first day of fall in 2025 is Monday, September 22.

Quick Scoop

Here’s what you need to know in one go:

  • Astronomical start of fall (Northern Hemisphere): Monday, September 22, 2025.
  • This date is set by the autumnal equinox, when day and night are almost equal in length.
  • In 2025, the equinox occurs at about 18:20 GMT (early-to-mid afternoon in U.S. time zones).

If you’re in the U.S. (any time zone), that same calendar day—September 22, 2025—is considered the official first day of fall.

Many people feel like fall starts sooner (pumpkin spice, cooler mornings, back-to-school vibes), but on the calendar, you’re waiting for that September 22 equinox in 2025.

Astronomical vs. “feels like” fall

  • Astronomical fall: Starts at the autumnal equinox, September 22, 2025.
  • Meteorological fall: Some weather and climate folks mark fall from September 1.
  • Cultural fall: Many forum and social media users jokingly call September 1—or even the first pumpkin spice latte drop—the “real” start of fall.

So if your question is “when is the 1st day of fall 2025” in the official seasonal sense, the answer is: Monday, September 22, 2025.

TL;DR: The first day of fall 2025 (astronomical/autumnal equinox) is Monday, September 22, 2025.

Information gathered from public forums or data available on the internet and portrayed here.