Autumnal Equinox 2020: The First Day of Fall

Facts & Folklore About the Fall Equinox

December 29, 2019
Autumnal Equinox - Fall Road
Pixabay

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. Why do we mark the equinox? Here’s all you need to know!

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; your clock time depends on your 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 the fall season in the Northern Hemisphere and 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 terms of length. (See more about this below.)

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, the sun is rising 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! 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:  As say that during an equinox, day and night is equal. Well, not exactly. It depends 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 lengths may be off by only a few minutes). 

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 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.

autumnal-equinox-fall.jpg

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

I live for autumn - my

I live for autumn - my favorite season! Every year I look forward to the sun shining brightly in our windows - but at a different angle than it did all summer. I also look forward to the bright clear days opposed to the very hazy days of our summer. These two signs tell me autumn is knocking at our door - and I welcome it!

Hello! Without a telescope,

Hello! Without a telescope, what do you see that harvest
moon worshippers can see between September 23rd, the Autumnal Equinox, and All Hallows EVE?

At 66 years of age, I am

At 66 years of age, I am between Boston, MA & C.Bus, OH., so I see a lot of different weather patterns. I have noticed, New England area getting LESS RAINS, past few years.

"The pleasure that is in

"The pleasure that is in sorrow", a poet has written, "is sweeter than the pleasure of pleasure itself." Hence the beauty of the fall of the year, and hence our particular delight in the spectacle it presents to our senses. It's a spectacle of decline, deterioration, and bereavement -- a melancholy spectacle. We respond to it for that very reason. We love the fall because of it's melancholy, not in spite of it.

The sweet sadness of the year's end doesn't set in until most of the autumn leaves are gone from the trees. The autumn colors are too bright and too busy to have the effect, though they point to it. It's when the leaves are brown, and few, and the branches and the trunks of the trees are gray that they begin to produce the emotional tone of this season, the tone of loss. The low skies of November, the dun ponds and frozen brooks, are a dark setting.

But although the season has a sorrowful character, it isn't a depressing time. On the contrary: The atmosphere of these last weeks before winter comes is the antithesis of depression. The senses -- the feelings -- become more receptive, educated by the stripped-down, impoverished look of the land. Maybe the last leaves, long dead, that hang on the trees are few in number, but you consider each one of them. Maybe the subdued little salt-and-pepper birds of November don't know many songs, but they have a companionable presence the brighter summer birds lack. In a part of the year that witholds the occasions for high spirits, the pleasure that we take is the pleasure of reflection, and it's keen, because it goes down deep.

Thanks, John, for the

Thanks, John, for the reflection on autumn. Those with eyes to see and a heart to feel will resonate with your observation that each season presents object lessons our own lives must pass through. Really appreciate your thoughts and invite you to share mine on chorusofcreation.wordpress.com Thanks again and best wishes.

Is it true that the more rain

Is it true that the more rain you get during Spring and Summer the greater the Fall colors will be?

For spectacular fall color,

The Editors's picture

For spectacular fall color, trees should have healthy growing conditions for spring and summer. In general, a warm, wet spring followed by a moderate summer. Then in fall, they need sunny, dry, warm days followed by dry, cool nights with temperatures above freezing. Other factors that affect color include species, plant health, genetics, shade, and soil moisture and fertility. A dry summer, for example, may cause the leaves to drop too early before they change. Too much rain may cause health problems for the tree, which may also affect fall color.

Two points: I still don't

Two points: I still don't know which month Autumn officially starts - and getting down this page to enter my comment was hard work

I agree about this page not

I agree about this page not specifying the month of the Autumnal Equinox!

In 2015, the autumnal equinox

The Editors's picture

In 2015, the autumnal equinox falls on September 23 at 4:21 A.M. (ET). 

I love Autumn. It is my

I love Autumn. It is my favorite season. To me it is the time the trees show off their finest leaves and and the nicest smells of wood smoke, and crisp fall air. Leaves to rake and jump in with your child or grand children, and then a harvest dinner of winter squash, corn, chicken,and apple pie.Parties,popcorn balls,candy apples bonfires, and friends. I'm anticipating it with a quiet excitement. :-D

Me too! It seems people

Me too! It seems people around me want summer to never end but I love the fresh, crispness in the Fall air and being able to wear jeans again!

Born this time of year. I

Born this time of year. I appreciate it more as an adult. Yes, I can hardly wait. Hosting a bonfire on HollowEve!

My favorite season is autumn.

My favorite season is autumn. I love the crisp air in the morning. I love to see the harvest moon lighting my pastures. The barely there outline of my horses breath when they breath. I don't mind the shorter days, I like the dark. I love Autumn. For some reason it makes me feel calm and cozy. The smell of firewood, the softness of a big fuzzy blanket around me as I sip a hot cup of coffee on my porch.....Ugh, I can't wait. Unfortunately, here in Gettysburg our Autumns only last a short while. I would love to live where it feels like fall most of the year.

I love autumn too. Hot drinks

I love autumn too. Hot drinks fire place going. Wearing sweaters scarfs and leggings. Cuddling on couch watching movies with my family. I wish I had a porch that would be beautiful. You have horses as well, I bet it's beautiful where u live. I'm from California. I replied to your comment because your description sounds so beautiful. Thank you for sharing, enjoy your autumn

Thank you.. I hope you

Thank you.. I hope you enjoy yours as well ! sorry misspelled breathe

it literally just turned fall

it literally just turned fall today (sept 23) and i already feel a HUGE difference. like literally yesterday it felt like summer and today it feels like winter. is the weather supposed to change that fast on the specific date? just feels kinda weird that the weather would change like that ON the specific date.

Yeah same here feels like

Yeah same here feels like everything has just got alot different I love autumn its my favourite time of the year looking forward to this one! :)

By the way, daylight savings

By the way, daylight savings time doesn't make the days any shorter or longer. It just shifts the time of sunrise and sunset by an hour.
If we stayed on daylight savings time all year, here in Seattle it would stay light until 5:15pm at Christmas, but the sun wouldn't come up until 9 am. If we never went on DST, on July 4th the sun would set at 8:15pm, but it would rise before 4 am! The further north you go, the more extreme it gets.
I have been in Alaska the last week of June and you can read a newspaper outside at midnight. You need eyeshades to sleep. I haven't been there in winter, but I understand the darkness drives some people to drink.
In Hawaii you hardly notice the difference between November and August.

Despite seeing "Daylight

Despite seeing "Daylight Savings Time" in print from time to time, the proper term uses the word Saving (singular). It is one example of terms and words which, because of common usage (MISusage, actually) give the impression of being acceptable. However, good literary form requires "daylight-saving time." (See "The Associated Press Stylebook.")

Your comment brings to mind

Your comment brings to mind the MISusage of the expression of "Happy New Years". Drives me nuts! Now Bill, if I don't see you until 2015, I shall now wish you a Happy New Year!
P.S. Enjoyed your comment.

It's true the days begin to

It's true the days begin to get shorter starting on the first day of summer way back in late June. But, the rate of shortening continues to accelerate until the autumn equinox in late September. In July, daylight might get shorter by only a few seconds or so each day so we don't notice it. But now, we lose 2 minutes on each end of the day every day, so 4 minutes less sun per day. That is a full hour less daylight in only 2 weeks from Sept. 15 to Sept. 29! We really notice that. And then, when daylight savings time goes away on Nov. 2, we are driving home from work in the dark ;(

The first thing I notice are

The first thing I notice are the bats. They begin emerging earlier each night in late August into September. Each day they'll get out a little earlier than the night before, from around 9:30 in July to 7:30 by mid-September. I also notice little breezes from the Northeast and Wooly Worms :)

Sorry, "things"

Sorry, "things"

Dang. It is a little

Dang. It is a little upsetting to see how many people despise Daylight Saving. I LOVE Daylight Saving! I LOVE summer and am always sad when it ends. Daylight Saving meant more outdoor play time as a kid. It means feeling safer leaving work in the evening. I get a little down when I walk out to my car after work when it is so dark, especially when it rains and I cannot see the deeper puddles to avoid them.

Yes, agreed. Summer is so

Yes, agreed. Summer is so freeing--no matter what your interest, you are free to pursue it. Nature is pulsing, pushing our new fruits and vegetables.
The ocean is roaring.
It is so good.

Yes summer may be loved in

Yes summer may be loved in your state, but where I live I could never possibly love summer. In Florida I'm pretty sure nobody likes summer. It's hot and humid more than usual especially when it rains. The only thing I like about summer is vacation. When fall starts to come it gets a little cooler then when winter comes even more so! I celebrate winter time and the middle of autumn, that's when it really gets the coldest. I really only like two seasons autumn and winter. Summer is not the best here. I wouldn't visit Florida during that time if I were you

I grew up in Florida. I

I grew up in Florida. I haven't lived there for many years. But I still miss the summers I spent as a youth. It was hot but I don't remember it being a problem. Even without air conditioning!

I lived in the Northeast for

I lived in the Northeast for 33 years then Florida for the last 7. I don't like heat but I never understand when people say that it is humid. We are surrounded by water and trees. OMG, I recall the atrocious summers in the northeast. When you step outside, it feel like someone is literally choking you. We just have more sun in Florida. Of course, I prefer winter, here but I do not miss the humidity up north at all. When it's 85 here, it's about 98 or 100 humid degrees in Chicago, NY, Mass, PA etc. Please note the daily temperature in all those states as opposed to FL. It is so much more relaxing here. I could never sit under a tree up north during the summer but I do it here. There's always a breeze.

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