Autumnal Equinox 2018: The First Day of Fall

Facts & Folklore About The First Day of Fall 2018

Autumnal Equinox - Fall Road
Pixabay

If you’ve sweated your way through a long hot summer, you might be ready for a change in season! The autumnal equinox—also called the September equinox—falls on September 22 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?

Although the equinox happens at the same moment worldwide, your clock times will depend on your time zone.

In North America, the autumnal equinox falls on September 22 this year at 9:54 P.M. ET.

(This translates to 8:54 P.M. CDT, 7:54 P.M. MDT and 6:54 P.M. PDT.)

Year Autumnal Equinox (Northern Hemisphere)
2018 Saturday, September 22
2019 Monday, September 23
2020 Tuesday, 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 spring in the Southern Hemisphere.

Why is it called an equinox? The word comes from the Latin aequus, meaning “equal” and nox, meaning “night.” 

During the equinox, the Sun crosses what we call the “celestial equator.” Imagine a line that marks the equator on Earth extending up into the sky above the equator from north to south. Earth’s two hemispheres receive the Sun’s rays about equally. The Sun is overhead at noon as seen from the equator, so at this point, the amount of nighttime and daytime (sunlight) are roughly equal to each other.

See the sunrise and sunset for YOUR location.

After the autumnal equinox, the nights will get longer and the days shorter until the December solstice near Christmas.

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

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 new 2019 Old Farmer’s Almanac!

Fall Foliage

Note that fall foliage isn’t due to current weather conditions. This is a common misperception. 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, “sunrises” 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 provide 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 it’s a bit of fun.  Try it! 

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

autumnal-equinox-fall.jpg

Nature’s Signs of Fall

What are you signs of fall? In many regions of North America, 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 then don’t forget about the end of Daylight Saving Time when you “fall” back, setting your clocks back one hour and regaining an hour of sleep.

Plants and trees are slowing down, as sunlight decreases. 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, Stonehedge 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!

Reader Comments

Leave a Comment

Your website for equinox

Beautiful pictures of fall scenery! I loved those photographs. They took my breath away. Thank you! informative site. Again, really beautiful photographs and art in general for all seasons!

First Day Of Fall

Your article says that the first day of fall is 9/22/2018, all of my calendars say that the first day of fall is on Sunday 9/23/2018, now which is right?

Fall

Both are correct. Fall begins the evening of the 22nd and the first full day of fall is the 23rd

Sept 22 or 23?

The moment of the equinox comes at the same time for everyone in the world, but it just depends on your clocks.  For UTC (Greenwich Meridian Time), this happens on September 23. 

We are a North American publication, so for continental U.S. and Canada, we mark the equinox on September 22. The exact time depends on your time zone (9:54 p.m. EDT, 8:54 p.m. CDT, 7:54 p.m. MDT and 6:54 p.m. PDT.)

The equinox itself is not technically a “day” such as the first full day of fall. It’s an astronomical moment in time when the Sun crosses the celestial equator as it moves from north to south.

 

Fall

Always an enjoyable time.
Cooler weather burst of cooler in the leaves of the trees . Good time for camping and hunting.

Gardners Instinct

Usually about 4 weeks before the seasons change, I get a sense that autumn is already in the air!

Me too

I start to notice the daylight is different than Spring and Summer. Almost as if the light is old. I don't know if it's just the changing angle of the sun or what but I do detect a difference.

Autumn light - Sunlight

Yes, I too have noticed a difference in light. I believe it is due to a shift, as the earth moves farther away from the sun.

It does have a very nice glow about it too!
Enjoy your fall season:)

Autumn Light- Sunlight

You are so right Valerie! I noticed the Glow myself. I just love Fall it's my favorite season. Blessings!

Hello Fall

As an early riser who enjoys the dawning of a new day, I miss the morning daylight as it arrives later in the morning. When I leave the house that beautiful ball of light and fire is in a different location. I've noticed that it isn't as hot. The temperature also has changed in the morning and at night. Good night summer, and hello Fall!

I could smell the difference

I could smell the difference in the air in the middle of July. And the color and look of the sky is different. The energy around me me is different as well. All of this in the middle of July.

July

I agree with you about beginning to see the Autumnal changes in late July, even here in Texas. I love the changing of the seasons! I believe in some cultures, they consider August 1 to be the beginning of autumn. Have a wonderful season!

Changing from Summer to Fall

I felt autumn a couple of weeks ago. It starts in July. The first inkling is the light starts to change. Predawn light starts a little later everyday. Dusk starts a little earlier everyday. I notice the sun is now in a different position in the morning and at dusk. Shadows are just a bit more pronounced.

FALL

Yes I felt it yesterday. was laying down looked out side and something about the lighting made me feel that fall was not far. Cant wait my favorite season.

FALL

Yes I felt it yesterday. was laying down looked out side and something about the lighting made me feel that fall was not far. Cant wait my favorite season.

September

Fall lasts 4 months, and Christmas lasts 3 weeks. I decorate for fall. The nativity is enough for Christmas.
"September" by Helen Hunt Jackson
1 The golden-rod is yellow;
2 The corn is turning brown;
3 The trees in apple orchards
4 With fruit are bending down.

5 The gentian's bluest fringes
6 Are curling in the sun;
7 In dusty pods the milkweed
8 Its hidden silk has spun.

9 The sedges flaunt their harvest,
10 In every meadow nook;
11 And asters by the brook-side
12 Make asters in the brook,

13 From dewy lanes at morning
14 The grapes' sweet odors rise;
15 At noon the roads all flutter
16 With yellow butterflies.

17 By all these lovely tokens
18 September days are here,
19 With summer's best of weather,
20 And autumn's best of cheer.

21 But none of all this beauty
22 Which floods the earth and air
23 Is unto me the secret
24 Which makes September fair.

25 'T is a thing which I remember;
26 To name it thrills me yet:
27 One day of one September
28 I never can forget.

The First day of Fall

This beautiful day will always be forever in my heart as the day I said "I do".

Outside with the changing leaves around us, my love and I became husband and wife.

We walked on a pathway of pumpkins and mums, to a floating stage of sunflowers.

Five years later and many memories made, we moved into our new home on the 22nd of September.

Fall

My Grandmother always said that it was never officially Fall until the Spider Lillies bloomed. I look for mine every year (they bloomed last week here). I think of her when I see them.

My animals tell me what kind of winter it's gonna be

When my cats and horses start getting thick coats early, I know the winter is gonna be COLD and hard. If they're slick up until Thanksgiving, I know a winter is gonna be mild.

Stink bugs! All over the

Stink bugs! All over the house. That's how I know fall is here.

How Do I Know It's Fall?

I know it's fall when the black walnut tree drops its green balls! We collect them and give them to our squirrels and chipmunks and they have a ball biting into them, running with them, storing them. The red squirrel is the quickest to grab them! : )

equal day and night

Wouldn't the day be slightly longer than the night, because of the diameter of the Sun? If it was a point source it would be exact, but it is not a point source.

day length

Daylight is longer than nighttime at the actual equinox, in part because the Sun is a disk, not a dot, and of the definition of sunrise and sunset, and therefore, length of day. Daytime is defined as beginning when the upper edge of the Sun reaches the horizon (which happens a bit before the center rises), and it doesn’t end until the entire Sun has set. So, that adds a little time (a few minutes) to daytime. If the Sun were a point, then we wouldn’t have those extra minutes. Also, because of our atmosphere, which bends light, the Sun appears a bit higher than it actually is. Therefore, it makes sunrise occur a little earlier and sunset a little later, which also adds a bit of time. How much time depends on latitude. It the Sun were a point, and we didn’t have atmosphere, then daytime and nighttime at the equinoxes would be 12 hours each.

For any day, you can find the rise and set times of the Sun, Moon, and planets, as well as day length, for your area, at this page:
http://www.almanac.com/astronomy/rise/

Hope this helps!

Autumn is coming

The darker early mornings that were once day. Especially around 6:30-7A.M.! Midday and early evening times seem more of a fall look in the sky as well. Some days, I smell the Autumn in the air around this time frame and it has that Autumn look and feel. Big giveaway is when the Georgia National Fair arrives in Perry, GA!! :0) Hope these helped or maybe someone else can relate to these signs I see and feel. Don't quote me on these! Just going by my OWN opinion!

How we know Fall is coming!

We live on a National Bicentennial Farm in the Blue Ridge Mountains of Virginia. We're fairly remote where we are in Grayson County, and our farm is surrounded on all sides by mountains. Because of this, we are very attuned to nature, and wild life. The mountains make a giant calendar all around us, where we can pinpoint any time of year by where the sun sets and rises, and at night mark the change in the position of the Milky Way. Also because of the mountains around us, there's an abundance of wildlife, and we can mark the coming of Fall by their changes as well. The crickets drown out the dawn chorus of the birds as Summer winds down, and as Fall approaches, they go all day and night as opposed to just at night. The second most prominent wildlife change is that the Screech Owls become far more vocal at night, when I hear those, I know Fall is on it's way! The cows become fussier because it's usually dry here at the end of Summer, and there's less choice grass for them to eat, meaning they have to be moved more often. Finally, the mountains themselves begin to change. Long before the leaves themselves turn, the mountains go from lush uniform green, to a very faint, but discernible undertone of different colors barely visible under the green of the leaves. Fall and Winter are my favorite times of year here, and I look for these signs every year to let me know that my first favorite season is on its way! I'm listening to those crickets right now!!

Beautiful description

Love your essay! Your description of the mountains being your calendar is very charming! Enjoy the upcoming beauty!

Your essay

The most beautiful feeling I've ever had just became words from your fingertips. Thank you.

Beautiful

Please keep writing about all the seasons on your farm! It sounds like the perfect place to be to witness their changes, and you have a wonderful way of describing them. Thank you.

How We Know Fall is Coming by M.S. Greene

You my friend, have a Greene thumb for writing.

Wonderful!

Sounds like you are living in Eden! Your descriptions are so evocative, I could just about smell the air where you are. You didn't need to attach a picture as you painted such perfect pictures in words, but I wish you had! Please share more! I'd like to think you feel pretty blessed to be on your place. Lovely, just lovely. Thank you.

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