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

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.

Florida is boring in the

Florida is boring in the cooler months. I love summer and spring here. More traveling and beaches. Recreation things to do. I only like warm winters. However, the government stinks here.

I love the early evening in

I love the early evening in the fall! It makes me want to be home out enjoying the cool early evening air for a bit, then inside to get warm with a warm meal. It reminds me of seeing the year pass by in school as a child, celebrating the holidays and events of the seasons as they pass by, rather than just having them pass by you once you are an adult with other responsibilities.

I agree! Not liking daylight

I agree! Not liking daylight savings time ... What?!?! I also am a summer girl! Always loving the out of doors & appreciating & DELIGHTING in the extra Light!!!!!

One of the things I love

One of the things I love about Autumn is the fact that the nights are getting longer. I'm not a fan of bright sun. I just wish that this Daylight Saving Time nonsense stopped for good. They keep changing the dates and experimenting with it. Either get rid of it completely or leave it alone. Well, being that tomorrow is the first full day of Autumn, it's time to make sure the gutters are clear, make sure the rake works, and to give the lawn one last feeding before its long Winter sleep.

Here in South Augusta,

Here in South Augusta, Georgia the tree called th water oak leaves just turn brown and fall. The only color we get is with the Maple, popular, and dogwood trees. I have had leaves falling since around 1st week of August, not much but enough to notice. By mid October I am working on getting leaves up until end of December or 1st week of January.

I love Fall because of the

I love Fall because of the seasonal festivities: Halloween, Dia de los Muertos, Thanksgiving, and the holiday season to be. We don't get much in the way of color in the leaves here in San Diego. The temps drop a bit, and the air is a litter crisper. But here in the southland there is an old saying that San Diego has four seasons, contrary to popular belief. They are Summer, Late Summer, Early Summer, and Next Summer.
Now if any of you snowbirds are heading this way, would you mind bringing some snow with you. We are in a bad drought.

Happy Late Summer!
Hasta Luego.

When the squirrels are

When the squirrels are crossing the roads carelessly carrying a too-big acorn, and I have to stop and tell them, "Be careful, little buddy!", while they circle back 22 feet when the road edge was 2 feet away, hypnotized by nuts, I know it's Fall. And when firewood ignored for months seems important, when I get to feel stiff dungarees and there is decreasing danger of bees and the apple trees I never spray draw deer with grown fawns from the neighbor's unnatural lawns, they come to see me. It's not just my tree nor the apples that fall in the Fall.

Very nice description!! So

Very nice description!! So poetic.

Hi, thanks. I wish I changed

Hi, thanks. I wish I changed the last word to 'Autumn' instead of 'Fall', it would have fit better with 'lawn' and 'fawn'. I was a friend of Millay's sister Norma, She might have liked it. You are bright, have a good day, and a pleasant Autumn.

Squirrels / Tree Rats Tomato

Squirrels / Tree Rats
Tomato / Tomahto

Up here in Vancouver and

Up here in Vancouver and nearby cities tree leaves are starting to turn into red and yellow. I love the smell of those pumpkin pies and Autumn is coming soon.

I love fall ♡

I love fall ♡

I LVU FALL more then any

I LVU FALL more then any thing i had a grandma born on fall day thats why i love falll

I've always loved spring and

I've always loved spring and summer. It's finally warm, you can go outside without being so covered you can barely move. Then I moved to Vegas. The person who commented before me was not wrong. I've spent the past 3 months naked inside my apartment, huddled next to a little fan. I wanted to go out and enjoy my time off school so badly, but I couldn't. I would need to down about 9 cups of water and take icy showers a few times a day just to stay sane. For literally the first time in my life, I can't wait to wear layers of clothes and sweaters! It's perfectly fine here the rest of the time and spring is just beautiful, but summers here have broken me a little bit..Please God, I NEED fall to happen. I just want to go back to when the peak heat was no higher than 80s, so I can actually do my schoolwork with a functioning brain.

I'm with you here in South

I'm with you here in South Florida and it has been miserable especially August can relate to the 9 cups of water when dehydrated muscles were hurting from excessive sweatingusually look forward to autumn this year not so much was supposed to go to Pennsylvania to see mom in spring to many of lifes publications in the way to make it in that time frame so still hoping to go all odds against me dreading seeing the autumn stuff in the stores this one time because if I don't make it soon I'm going to have to cancel till spring again once Halloween hits it's all downhill from there no time for nothing elsebut on the brighter side once the holidays hit at the time I like to stay in the house and do homie things happy autumn everybody sunny South Florida

Fl. Sucks, live in the

Fl. Sucks, live in the panhandle. Cooking turkey on Thanksgiving in shorts and opening presents at Christmas in shorts and then maybe in late feb or early mar a few days of below 32 deg. Wowee I would rather live where there are actual seasons again. Here in FL you can never get enough clothes off it's far easier to live where the humidity below 85% atleast in the Rockies there are leaves that change colors here we have pi e trees scrub oaks and palmetto bushes that stay green year 'round........

If u don't love it - leave

If u don't love it - leave it!

Please don't make it sound

Please don't make it sound like we are holding you hostage in Fl. You can leave at anytime and go live where you WANT to be!!