when is fall
Fall has two common “start dates”: by the calendar, it begins 1 September and runs through 30 November, and by astronomy, it begins at the autumnal equinox around 22–23 September and runs to the winter solstice around 21–22 December in the Northern Hemisphere.
Quick Scoop: When Is Fall?
Think of fall as having two overlapping definitions, plus a cultural one people use in everyday life.
1. Meteorological fall (weather/calendar)
Meteorologists divide the year into neat three‑month blocks that match typical temperature patterns.
- In the Northern Hemisphere, fall runs from 1 September to 30 November under this system.
- This makes climate statistics and record‑keeping simpler, since the dates never change.
So if someone asks “when is fall?” in a weather or climate context, they usually mean September, October, and November.
2. Astronomical fall (Sun and equinox)
Astronomical fall is tied to Earth’s position around the Sun.
- Start: Autumnal equinox, when day and night are nearly equal and the Sun is directly over the equator, usually around 22–23 September in the Northern Hemisphere.
- End: Winter solstice, around 21–22 December.
- Under this definition, fall lasts roughly 90 days.
Many “official” season calendars, holiday sites, and space/astronomy references use this astronomical definition.
3. How people actually talk about fall
Everyday usage is messier and more emotional, often based on vibes—cooler air, changing leaves, and holidays.
Common informal markers in the US and similar climates include:
- “Fall starts after Labor Day ” (first Monday in September) for many people.
- Some feel it’s not really fall until October , when leaves change color and it “smells” like fall.
- A lot of people stop thinking of it as fall once December and winter holidays arrive, even though astronomical fall runs into late December.
Online forum discussions show three popular answers to “when does fall start?”
- September 1 (meteorological).
- Around September 22–23 (equinox).
- “When it finally cools off where I live,” which can be late September or even October in warmer regions.
4. Northern vs. Southern Hemisphere
The timing flips between hemispheres.
- Northern Hemisphere: fall is centered on September–November (meteorological) or late September–late December (astronomical).
- Southern Hemisphere: fall is centered on March–May and starts at the March equinox.
5. At‑a‑glance table (Northern Hemisphere)
| Definition | Typical start | Typical end | Who uses it? |
|---|---|---|---|
| Meteorological fall | 1 September | 30 November | Weather/climate agencies, many everyday calendars | [1][7][8]
| Astronomical fall | Autumnal equinox (~22–23 September) | Winter solstice (~21–22 December) | Astronomy references, some “official” season lists | [4][8][9][10][3]
| Informal “feels like” fall | After Labor Day or first cool, leafy days | Often by late November | Everyday speech, forum discussions, cultural habits | [8][9][5]
In plain terms: if you’re talking weather, fall is September to November; if you’re talking Earth–Sun geometry, fall starts at the late‑September equinox.
TL;DR:
- Calendar/weather answer: Fall = 1 September to 30 November (Northern Hemisphere).
- Astronomy answer: Fall = autumnal equinox (~22–23 September) to winter solstice (~21–22 December).
Information gathered from public forums or data available on the internet and portrayed here.
