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

Leave a Comment

Love this time of year!

Love this time of year! Nature is preparing to rest. The winds are blowing crisp and there's a freshness in the air! The days have become comfortable and the chilly nights make for a restful sleep. Love cooking "comfort" foods that puts a smile my family's face.

I would love to receive your

I would love to receive your emails and updates.

Hi, Meleca, Thanks! You can

The Editors's picture

Hi, Meleca, Thanks! You can sign up for our free e-newsletter updates on this page:

The one thing I DON'T hear

The one thing I DON'T hear that tips me off to autumn approaching, is the lack of singing birds that would wake me every morning during spring and summer. The shorter days is another hint. I never did like autumn because of the shorter days and eventually all of nature goes to sleep in a hibernation to be followed by winter and cold.

All your singing birds that

All your singing birds that you miss have flown down here to Florida for the winter...sorry about that.

Even in southern NJ where the

Even in southern NJ where the temps are still in the 80's fall is starting to show Her face.The Monarch butterflies are heading south for the winter.

Southern, NJ: Are you around

Southern, NJ: Are you around Cape May? Send those Monarch's down here, I have not seen one yet in my North Carolina garden and I am impatiently awaiting their arrival. Fall is coming slowly here. The goldenrod is out in bunches and a bright yellow wild daisy that I am not sure of its name but it is so bright and cheery. I note this afternoon that they are nearly all gone with the torrents of rain we had last night. The Crepe Myrtle is still in bloom as are the knock-out roses popular around here. Grandson Jack and I dug up the potatoes this week and at least this year we have enough for supper--last year there were only 3 small "marbles"--abundant rain made the difference this year for sure. The flowers are giving their all in their last push of the year and it is marvelous. Happy Equinox! As the ancients celebrated this day, so should we to praise the marvels of nature.

Hummingbirds left the day

Hummingbirds left the day before Labor Day. A 14 foot Eastern Diamondback was spotted in a field nearby. It has rained nearly every day for the entire month of August near Savannah, GA

our fall looks like it's

our fall looks like it's begun in july here in mich the oaks have been shedding leaves since then and since it's been dry. i doubt we'll have the spectacular colours we normaly have.

Here in Tennessee Autumn is

Here in Tennessee Autumn is on its way! It is the deeper blue color in the sky, that notice first. I have already seen this beginning. :) So happy!

We're in the Knoxville area

We're in the Knoxville area and while it's better (read: cooler) than it was, it's still never cool enough for me. I'm a transplanted northeasterner from Pennsylvania and I LOVE Autumn and I LOVE Winter. You can keep the other two seasons! I can't stand temps over 60 degrees Fahrenheit!

The monarch butterflies are

The monarch butterflies are just beginning their magration through OK. Every two or three days, one flutters through my backyard.

Your article says "From here

Your article says "From here on out, the temperatures begin to drop and the days start to get shorter." Actually, the days start getting shorter after the summer solstice, up until the winter solstice when they start to get longer. The autumnal equinox is when the days start to get shorter than the nights (before the equinox the days are longer than the nights).

wow i loved your writing of

wow i loved your writing of fall. The summer comparing to dragons breath is perfect. I felt like was on a real travel as i read along. Awesome thanks.

YAAYY just 7 weeks till we

YAAYY just 7 weeks till we enter Virgo Pass and leave the hot dragon breath of summer xD The last month of summer 8/22 - 9/22 is the most beautiful and amazing to see. The first 2 weeks are the hottest of days as the stubborn heat from August tries desperately to hold on. Each day gets hotter and drier up the imaginary high mountain pass of Virgo - sorta like seeing the dry side of the Cascade mountains in Washington State where temps can top over 100 deg. Then about Sept 11th the midpoint is reached and there's this blast of cool air that's never been felt before from the Libra side of the mountains. The air is crisp clean and has a beautiful chill that tames the fiery dragon breath of summer. Once over the pass and below the Virgo summit in the last 2 weeks of summer, the nights get chillier and outweigh the warmth and the grasslands begin to change into an array of color. Much like the Seattle side of the Cascades where the temp can be 40 degrees cooler in a matter of a few miles, that sudden drop in temps is enough to tip the scales of fall into full swing and each day the woodlands come more alive in color as the days shorten further. The most amazing image in my mind is descending the high mountains after so much summer discomfort and suffering and seeing the crisp clear waters of Scorpio Sound with the height of fall foliage around it's pristine shores. The beautiful fall landscape around the wooded city of Libra is like the perfect city that lives harmoniously in it's own environment allowing people and nature to live together in peace and thanksgiving. I cry every year living to see this beautiful season begin and like spring, fall can be very much like heaven on Earth YAAYY!

Thank you for the trip

Thank you for the trip through the Autumn signs. I was born just after the Virgo Libra cusp, and have always paid more attention to the season.
I love your description as it echoes within my soul.
Thank you and bless you

I live in the panhandle of

I live in the panhandle of Idaho and about 60 to 70 miles from Canada. Which issue of the almanac should I buy? I am new to the area and am a little unsure? San Francisco is a lot further away.

Here in Mena,Arkansas. We

Here in Mena,Arkansas. We have had a few cool mornings. The leaves are just starting to change color. I myself looking for a bad winter. It's been hot and dry all summer.

On around August 15th I can

On around August 15th I can smell Fall in the air, the smell, the feel, it changes on that date. The squirrels are noisy now. Chirping and scurreying about storing food. Sleeping and sleepiness is of high quality as it is warm in the day and cool at night.

I tend to notice the changes

I tend to notice the changes in sounds first...I noted this in my journal a week or so ago:
The cicadas have ceased singing but the crickets have taken up the chorus.

that's really a nice

that's really a nice perspective! I found this poem you might enjoy too!

November Night

Listen. . . .
With faint dry sound
Likes steps of passing ghosts,
The leaves, frost-crisped, break from the trees
And fall.

Adelaide Crapsey

Autumn is beautiful for such

Autumn is beautiful for such a short time. The bright bold colors of the leaves,the mums,apples,pumpkins,indian corn,here to say their goodbyes in a colorful fiesta...then...gray flannel till spring.

The above article states that

The above article states that "From here on out, the temperatures begin to drop and the days start to get shorter." This is not accurate as the days start getting shorter after the summer solstice. I think what the article may have meant to say is that the days start getting shorter than the nights, i.e., there is more darkness than light in a 24 hour period.

The article did say that, you

The article did say that, you should pay closer attention.

Here in San Francisco, Fall

Here in San Francisco, Fall shows up w/Arctic Terns stopping by on migration South, pole to pole, BIG migration. xoxoxo, L

I love the change of seasons.

I love the change of seasons. When my grandson was 4 yrs he asked why the trees changed. Trying to explaine so a 4 yr. old could undeersta, I told him in the fall trees are puting on thier pj's, in the winter they were asleep, and in the spring when they woke up, they were green again.
I've really noticed the birds flocking togeather. Fall is on the way

The first signs of fall I see

The first signs of fall I see every year is wolf spiders and wood spiders moving into my house. I love fall, but absolutely hate spiders. There's been four meet untimely deaths so far, there'll be 50 more at least before the snowflakes fall.

what the hell!! U need to go

what the hell!! U need to go to the store and by some raid bombs and set them off in ur house every two weeks or once a month all through out the fall and winter season mate. All of them will die :-D

Spiders are very beneficial

Spiders are very beneficial to our enviromnent, I never hurt one...