Autumnal Equinox 2019: The First Day of Fall

Facts & Folklore About Fall

September 5, 2019
Autumnal Equinox - Fall Road
Pixabay

In 2019, the autumnal equinox—also called the September equinox—will arrive on September 23 in North America. Wondering why it’s called an equinox? 

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

When is the Autumnal Equinox?

In 2019, the autumnal equinox occurs on Monday, September 23, at 3:50 A.M. EDT. The equinox occurs at the same moment worldwide; adjust for your local time zone.

Year Autumnal Equinox (Northern Hemisphere)
2019 Monday, September 23
2020 Tuesday, September 22
2021 Wednesday, September 22
2022 Thursday, 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 fall in the Northern Hemisphere and of spring 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 terms of length.

During the equinox, the Sun crosses what we call the “celestial equator”—an imaginary extension into space of Earth’s equator line. 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, nights begins to grow longer than the days. 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! Find out the forecast for your area in The 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: No. Even on the equinox, day and night aren’t perfectly equal! However, they are very close to equal (the lengths may be off by only a few minutes). Why does this happen?

It depends where you live. On the equinox, the center of the Sun is 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 longer than 12 hours.

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 actually see the Sun before the edge actually reaches the horizon! This causes daylight to be longer than 12 hour as well.

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

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, but it’s not just on the equinox. Still, it’s a bit of fun. Try it yourself! 

See more fun facts and myths about the old, misunderstood equinox from Almanac astronomer, Bob Berman.

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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.

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Reader Comments

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What determins when the

What determins when the autumn leaves change? Temp and/or length of daylight?
Tks!
Brad

Answer: Length of daylight.

Answer: Length of daylight. ;-}

Actually, it's more an effect

Actually, it's more an effect of the temperature, as it's the freeze that kills the chlorophyll not the hours of sunshine. However when there are more hours of sun it's more likely to give the chlorophyll a chance to rebound. Not to mention shortening the time it's exposed to the colder temperature.
God bless

Here in southern Ohio, the

Here in southern Ohio, the leaves are slowly changing; others have already turned and fallen off completely! But I absolutely love fall and all that comes wit it...bonfires, Halloween, gorgeous scenery and beautiful walks through the park. Happy Fall to all! Have a great day! :)

Sunrises and sunsets are

Sunrises and sunsets are different in the fall. The air smells fresh and crisp and it's refreshing on your face. I like driving with the heat on and windows rolled down.

This is my favorite time of

This is my favorite time of year! There's nothing like the smell of pumpkin bread in the oven and a pot of hot coffee brewing. Walking outside and hearing the crunching leaves underfoot. Truly the best time of the year!

I know it's autumn when I see

I know it's autumn when I see nuts on the ground around my house. It means the squirrels are doing their winter gathering...and inadvertent scattering.

WE LOVE THE FALL! Hello,

WE LOVE THE FALL! Hello, stars in the sky!! @--)-- :O)

My Hummers are gone

My Hummers are gone And my Cosmos petals have fallen But, I know more's in store And that's why I'm not bawlin'
~Patti Poff~

From Chicago . the leaves are

From Chicago . the leaves are starting to turn, the crickets and grasshoppers are gone from the garden, the nights are cool, the days heavenly, flannel shirt weather. The squirrels are busy burying the acorns and the smell of firewood is in the air. I wait all year long for September and October and they just fly by.

Welcome Autumn! Here in

Welcome Autumn! Here in north-central California our daytime temperatures are still fairly hot (90-ish), with our nights cool 60-ish). We've had a very dry summer and need rain desperately. No real signs of autumn yet, but hopefully there will be soon.

I grew up in the midwest and

I grew up in the midwest and love fall and the leaves changing colors!! I miss the leaves changing colors, raking the up, and jumping into the big huge pile of leaves!! Here in Phoenix we have a FEW more days of 100+ days of hot weather!!! Then it just might start to cool off into the middle to high 90's!!! Wish it would cool off more!!! Really miss the days of Fall of Wisconsin!!!!

Autumn

Nothing like Wisconsin seasons :)

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.

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

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