Autumnal Equinox 2020: The First Day of Fall

Facts & Folklore About the Fall Equinox

September 18, 2020
Autumn in Colorado

In 2020, the autumnal equinox—also called the September equinox or fall equinox—arrives on Tuesday, September 22. Fall begins in the Northern Hemisphere and spring begins in the Southern Hemisphere. Read about the signs of fall and the ways we mark the approaching equinox. 

Autumn has caught us in our summer wear.
–Philip Larkin, British poet (192286)

When Is the Autumnal Equinox?

The fall equinox arrives on Tuesday, September 22, 2020, at 9:31 A.M. EDT. The equinox occurs at the same moment worldwide.

Autumnal Equinox Dates and Times

Year Autumnal Equinox (Northern Hemisphere)
2020 Tuesday, September 22
2021 Wednesday, September 22
2022 Thursday, September 22
2023 Friday, September 22

What Is the Autumnal Equinox?

Autumn days come quickly, like the running of a hound on the moor.
Irish proverb

The autumnal equinox—also called the September or fall equinox—is the astronomical start of the fall season in the Northern Hemisphere and of the spring season in the Southern Hemisphere.

What Is an Equinox?

The word “equinox” comes from Latin aequus, meaning “equal,” and nox, “night.” On the equinox, day and night are roughly equal in length. (See more about this below.)

During the equinox, the Sun crosses what we call the “celestial equator”—an imaginary extension of Earth’s equator line into space. The equinox occurs precisely when the Sun’s center passes through this line. When the Sun crosses the equator from north to south, this marks the autumnal equinox; when it crosses from south to north, this marks the vernal equinox.

After the autumnal equinox, the Sun begins to rise later and nightfall comes sooner. This ends with the December solstice, when days start to grow longer and nights shorter.

Fall bridge

Fall Weather

It is the summer’s great last heat,
It is the fall’s first chill: They meet.

–Sarah Morgan Bryan Piatt

Another definition of fall is “nights of below-freezing temperatures combined with days of temperatures below 70 degrees Fahrenheit (21°C)”. From here on out, the temperatures begin to drop.

Will fall bring crisp, cool weather—or, unseasonably warm weather? It depends on where you live! See our 2020 Fall Weather Forecast.

Find 12 months of long-range weather predictions in the new Old Farmer’s Almanac!

Fall Foliage

Note that fall foliage isn’t due to current weather conditions. This is a common misconception. Leaves change color because of the amount of daylight and photosynthesis. Learn more about autumn leaves.

Japanese maple leaf in fall

Fall Equinox FAQs

Q: Are Day and Night Perfectly Equal on the Equinox?

A:  Some say that during an equinox, day and night is equal. Well, not exactly. It depends on where you live.

On the equinox, the center of the Sun is indeed above the horizon for 12 hours. However, “sunrise” is said to begin when the upper edge of the Sun’s disk becomes visible above the horizon (which happens a bit before the center rises) and ends when the entire Sun has set. In this case, daylight is still a bit longer than nighttime. 

Not only that, but the Sun is actually visible when it is below the horizon, as Earth’s atmosphere refracts the Sun’s rays and bends them in an arc over the horizon. Yes, you can see the Sun before the edge actually reaches the horizon! This causes daylight to be longer than 12 hours as well.

However, they are very close to equal (the total lengths may differ by only a few minutes). 

Did you know our rise/set tool now provides day length? In Dublin, New Hampshire, USA—home of The Old Farmer’s Almanac—our day length on the equinox is 12:08 hours.

See our Sunrise/set calculator for day length in YOUR area.

Q: Is the Autumnal Equinox Really the First Day of Fall?

A: Based on the astronomical definition of seasons, yes, the autumnal equinox does mark the first day of fall (in the Northern Hemisphere). However, according to the meteorological definition of seasons, which is based on temperature cycles and the Gregorian calendar, the first day of fall is September 1.

Q: Can You Balance An Egg On the Equinox?

A: There’s an old-wife’s tale that you can stand an egg on its end of the equinox. Well, yes, it’s true (and fun to try). But it’s not only on the equinox. See more about equinox facts from Almanac astronomer, Bob Berman.

autumn woods

Signs of Fall

What are your local signs of fall? In many regions of the Northern Hemisphere, the landscape silently explodes with vibrant colors of red, yellow, and orange. The leaves begin to drop off the trees, providing endless hours of jumping into leaf piles for kids and raking them back up for parents!

Trees snapping and cracking in the autumn indicate dry weather.

Fall also brings some wonderful holidays, including Halloween and Thanksgiving, which carry us through the season until temperatures begin to drop, nights begin to get longer, and all the woodland critters start storing up for the long haul of winter

And don’t forget about the end of Daylight Saving Time, when we “fall” back, setting our clocks back one hour and regaining an hour of precious sleep!

Plants and trees are slowing down, as sunlight decreases, to get ready for the colder season ahead. In the garden, asters and chrysanthemums bloom beautifully as orange pumpkins and corn mazes abound.

Football season is warming up and so is sweater weather.

Also notice the arc of the Sun across the sky each day as it starts shifting south. Birds and butterflies migrate along with the path of our Sun!

Of course, you can you can easily notice the later dawns and earlier sunsets. See our sunrise/set tool for your area!

Purple Aster
Aster flowers

Ancient Autumn Traditions 

The fall equinox has been a day of celebration for cultures since ancient days. People tracked the transitions of the Earth’s journeys around the Sun.

  • At Machu Picchu in Peru, an ancient stone monument called Intihuatana—which means “Hitching Post of the Sun”—serves as a solar clock to mark the dates of the equinoxes and solstices.  
  • In Mexico, the Mayans built a giant pyramid called Chichen Itza. On the equinoxes, it looks as if a snake made of light slithers down the pyramid’s steps.
  • In England, Stonehenge was also built with the equinoxes and solstices in mind.

See Five Ancient Sites Aligned With the Equinoxes and Solstices.

Enjoy Autumn!

Wishing a colorful, cool, cozy autumn to all our Almanac readers. Tell us your favorite things about the fall season below!

To learn more about all four seasons and see when they begin, see First Day of Seasons.


Reader Comments

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wowwe . Try freezing your

wowwe . Try freezing your b----ls off Christmas or cold drizzle on T-day sliding off the Ivey road in the freezing rain come on up north its fun

I would LOVE that. I HATE

I would LOVE that. I HATE cold. I am going to move to Florida soon. I'm done with Missouri winters. Ugh.

I've been in Chicagoland, too

I've been in Chicagoland, too cold. I've been in eastern Carolina, couldn't complain. And now I'm close to Austin, it's great. I like an 88F house and I don't care if it gets over 100F outside with full sun to enjoy. That's actually the temperature I love to be outdoors in. I don't sweat indoors till after 88F as long as a tiny bit of air is moving. And yes, I love to live naked. I hate clothes and until winter things are great. 82F is when things starts getting cold and I wish for summer heat. You might think I'm old, to enjoy the heat, not at all. I just acclimate to heat well, and what is eaten and drank all plays a large part in that. Hint: too many simple carbs, or a carb heavy diet let you overheat easily.

Robot, Having survived 11

Having survived 11 summers in Vegas, I can commiserate. Fall is what keep you sane May through Oct! I love fall, particularly now that I no longer live in the desert.

I understand why Northerners

I understand why Northerners love Summer... no deep freeze.

But here in Vegas I LOATHE the heat. 100 - 115 ever day for months. I wait every day for fall. It signals a good 8 or 9 months of livable weather.

The temps cool off enough where you can actually go outside and do something without passing out from the oppressive, searing, oven-like heat.

Plus Halloween, Thanksgiving & Christmas are on the way. What could be better?

I <3 Autumn!

I totally agree with you Reno

I totally agree with you Reno isn't far behind Vegas as far as weather in the summer. I lived with it for over 10 years, finally had enough and came home to the RAIN and Evergreens(trees). Now I am in eastern Oregon more of the same type weather in June and July.

Vegas?? Sorry but you don't

Vegas?? Sorry but you don't know miserable heat as most would call it until you live in south Texas. Not only the temps but the humidity, I love the heat but hate the humidity.

Y'all have a great day,

That goes double for

That goes double for Phoenix.
Not only do the daytime high temps stay over 100 for 3 months, the nighttime low temps seldom drop below 90.
Then you can add in the "monsoon" moisture that pushes dew points into the 60's almost every day. Not Florida humid, but pretty bad when paired with 110 degree heat.
So to summer I say each year: "Good Riddance"!

it becomes fall up here in

it becomes fall up here in Alaska when it either gets dark at 9 P.M. or when there's no green leaves on the trees (not evergreens) which ever comes first.

Autumn is in the air!! The

Autumn is in the air!! The light is noticeably angled, more golden and hushed here in Texas. School has started, trees will be changing colors, stores are selling sweaters in gorgeous autumn hues, football games are being played, what an exciting time of year! Scorpio with its orange star Antares is sliding Westward, and Spica is almost setting with the sun. I can't wait for that first touch of crispness in the air!! Everything about Autumn is just wonderful!! The smells - apples, cinnamon, spiced pumpkin pies, wood fires burning, are so alluring! Sunsets are so colorful right now as well. Thank you OTF and fellow readers for sharing thoughts and joy on this magical time of year!

I couldn't of said that any

I couldn't of said that any better. You put it in the way that I feel. Fall is to me the best season. I love sitting out side with a cup of coffee and with my blanket that my Baba knitted me and reading a good book. I can't wait for fall every year and I'm counting the day! But what you said was so nicely put. :)

I love your idea of reading

I love your idea of reading outside in the autumn light! I hope you get to enjoy many gorgeous days all cozy in your warm blanket! I love coffee too and it seems to taste and smells better in the fall and winter! Have you ever googled 'autumn quotes'? There's several good websites with beautiful poems and thoughts that I think you'd love! Happy Autumn 2014!!

I couldn't agree with you

I couldn't agree with you more, i think autumn is so magical from tree leaves changing colors, the chilly mornings and evenings, to the smell of cinnamon and spice. I can't wait for autumn to start here in SC!!!

Hey Marybeth Shipley, try

Hey Marybeth Shipley, try breaking your Prozacs in half for now on. Fall is as exciting or boring as any other season.

I LOVE the fall! It's the

I LOVE the fall! It's the start of all the wonderful holidays and gets my family geared up for Thanksgiving and Christmas. This truly is the start of the most wonderful time of the year!!

I agreed with you is a

I agreed with you is a wonderful feeling

autumn is colorful but sad to

autumn is colorful but sad to see the summer pass.

I know a lot of people love

I know a lot of people love the summer I live in California and I just can't handle the heat, sometimes it gets sticky and I really love the fall season because I know the relief is on the way

Agreed. Summer was great

Agreed. Summer was great when I was a kid (& for kids now), but I don't care for it (as an adult). I always look forward to fall...cooler weather & football and hunting season.

I love the fall season.

I love the fall season. Summer in the south is misserable. It would be nice to have fall and winter only.

Why did you Americans change

Why did you Americans change the name of Autumn to "fall"
Actually I am trying to find the right dates when the seasons start. I reckon 21/3 etc but here in NZ they reckon the 1st of the month.

from Wikipedia: The

from Wikipedia:

The alternative word "fall" for the season traces its origins to old Germanic languages. The exact derivation is unclear, with the Old English fiæll or feallan and the Old Norse fall all being possible candidates. However, these words all have the meaning "to fall from a height" and are clearly derived either from a common root or from each other. The term came to denote the season in 16th century England, a contraction of Middle English expressions like "fall of the leaf" and "fall of the year".[12]

During the 17th century, English emigration to the British colonies in North America was at its peak, and the new settlers took the English language with them. While the term fall gradually became obsolete in Britain, it became the more common term in North America

The name Fall is actually a

The name Fall is actually a very old English term for Autumn. t was used in the UK in medieval times, before the Americas were discovered. It was us Brits who changed it to autumn!

My birthday is on the spring

My birthday is on the spring equinox and my sisters is on the fall equinox. We do not get along,never have. Does us not getting along have to do anything with our birthdays?

I don't think the saason has

I don't think the saason has nothing to do with you or your sister maybe you don't get alone because you have your dads personality and your sisters your moms

Its my belief that the

Its my belief that the seasons,moon& sun changes all play a role in both personality and behavior. Working in health care I have seen this first hand.

I was born on the cusp Dec.

I was born on the cusp Dec. 21 and do not get along with Geminis who are my polar opposite. Sag/Caps have this problem sometimes. Don't know about spring equinox though.

my birthday is on the same

my birthday is on the same day as when Autumn begins :D

Well, here in upstate NY

Well, here in upstate NY state, I'm wondering why the leaves are still 99% green and we're still having beautiful days in the mid 70's. I'm not complaining but I'm wondering what the old wives tales say about this; does it mean we're going to have a dreadful winter? Autumn is pretty but I have to admit a feeling of dread and sadness every autumn. I HATE cold weather and winters here are just plain awful; not my cup of tea, but I guess there are people who love winter. Even though it's still cold in the spring, to see all the nature coming back to life and becoming green is just an uplifting feeling! Sometimes I wish I could move to a place where it's beautiful warm weather all year, with no earthquakes, hurricanes, tornadoes, floods, extreme heat, etc. Is there such a place on earth?

Dear Ms. Taratuchin,

Dear Ms. Taratuchin,
Yes, I am sure there is a place on some island. New Zealand is a nice place. And Arizona is nice in the winter with none of the things you said, such as hurricanes. They can have dust storms, but mostly in the more desolate desert up in Phoenix and they can have floods, but the Southern Arizona has been in a drought for about 10 years, though they can some rain in the summer.