The official astronomical start of fall (autumn) in 2025 is on Monday, September 22, at 2:19 p.m. Eastern Daylight Time (EDT). This corresponds to the autumnal equinox when the sun crosses the celestial equator. Meteorologically, fall is often considered to start earlier on September 1 and lasts through November 30. Both definitions are commonly used, with the astronomical fall tied to the equinox event and meteorological fall based on calendar months for consistency in weather statistics.
Astronomical Fall Start
- Occurs at the autumnal equinox.
- In 2025, it is September 22 at 2:19 p.m. EDT.
- Marks the day when day and night are approximately equal in length.
- Happens due to the tilt of Earth's axis and orbit around the Sun.
Meteorological Fall Start
- Starts on September 1 and ends on November 30.
- Used commonly by meteorologists for easier statistical comparisons.
- Divides seasons into fixed three-month segments.
Thus, fall officially starts with the autumnal equinox on September 22, 2025, astronomically, but meteorological fall started on September 1, 2025, in many places.
