When Do the Seasons Start in 2021?

Celebrate the First Days of Spring, Summer, Fall, and Winter

January 1, 2021
Spring, Summer, Fall, Winter 360

When do all of the four seasons—spring, summer, fall, and winter—start and end? Find your equinox and solstice dates for 2021 and 2022—plus, learn the difference between an astronomical season and a meteorological season.

When Do the Seasons Begin?

Each season has both an astronomical start and a meteorological start. It sounds complicated, but trust us, it’s not! The astronomical start date is based on the position of the Sun in relation to the Earth, while the meteorological start date is based on the 12-month calendar and the annual temperature cycle. See below for a more in-depth explanation.

The First Days of the Seasons

Seasons of 2021 Astronomical Start Meteorological Start
SPRING Saturday, March 20, 5:37 A.M. EDT Monday, March 1
SUMMER Sunday, June 20, 11:32 P.M. EDT Tuesday, June 1
FALL Wednesday, September 22, 3:21 P.M. EDT Wednesday, September 1
WINTER Tuesday, December 21, 10:59 A.M. EST Wednesday, December 1
Seasons of 2022 Astronomical Start Meteorological Start
SPRING Saturday, March 20, 11:33 A.M. EDT Monday, March 1
SUMMER Sunday, June 21, 5:14 A.M. EDT Tuesday, June 1
FALL Wednesday, September 22, 9:04 P.M. EDT Wednesday, September 1
WINTER Tuesday, December 21, 4:48 P.M. EST Wednesday, December 1

Note: The dates above correspond to the start of the listed seasons in the Northern Hemisphere. Times are based on Eastern time (ET). Subtract 3 hours for Pacific time, 2 hours for Mountain time, 1 hour for Central time, and so on.

Definition of “Season”

What exactly is a “season”? Astronomists and meteorologists define seasons differently. 

  • The astronomical start of a season is based on the position of the Earth in relation to the Sun. More specifically, the start of each season is marked by either a solstice (for winter and summer) or an equinox (for spring and autumn). A solstice is when the Sun reaches the most southerly or northerly point in the sky, while an equinox is when the Sun passes over Earth’s equator. Because of leap years, the dates of the equinoxes and solstices can shift by a day or two over time, causing the start dates of the seasons to shift, too.
  • In contrast, the meteorological start of a season is based on the annual temperature cycle and the 12-month calendar. According to this definition, each season begins on the first of a particular month and lasts for three months: Spring begins on March 1, summer on June 1, autumn on September 1, and winter on December 1. Climate scientists and meteorologists created this definition to make it easier to keep records of the weather, since the start of each meteorological season doesn’t change from year to year.

Because an almanac is an astronomical “calendar of the heavens,” The Old Farmer’s Almanac follows the astronomical definition of the seasons.

Temperate regions of Earth experience four seasons because of shifting sunlight, which is determined by how the Earth orbits the Sun and the tilt of our planet’s axis.

As the Earth progresses through its orbit during the year, the tilt causes different parts of the Earth to be exposed to more or less sunlight, depending on whether we are tilted towards or away from the Sun.

Equinox solstice cycle
Photo Credit: NASA

Why Are The Seasons Different Lengths?

It can sometimes feel like winter is dragging on forever, but did you know that its actually the shortest season of the year? (In the Northern Hemisphere, that is.)

Thanks to the elliptical shape of Earth’s orbit around the Sun, Earth doesn’t stay the same distance from the Sun year-round. In January, we reach the point in our orbit nearest to the Sun (called perihelion), and in July, we reach the farthest point (aphelion). Read more about perihelion and aphelion.

When Earth is closer to the Sun, the star’s gravitational pull is slightly stronger, causing our planet to travel just a bit faster in its orbit. For those of us in the Northern Hemisphere, this results in a shorter fall and winter, since we are moving faster through space during that time of the year. Conversely, when Earth is farthest from the Sun, it travels more slowly, resulting in a longer spring and summer. (The opposite is true in the Southern Hemisphere.)

In other words, it takes Earth less time to go from the autumnal equinox to the vernal equinox than it does to go from the vernal equinox to the autumnal equinox.

Due to all this, the seasons range in length from about 89 days to about 94 days. 

The Four Seasons

What defines each season? Below is a brief explanation of the four seasons in order of calendar year. For more information, link to the referenced equinoxes and solstices pages.


On the vernal equinox, day and night are each approximately 12 hours long (with the actual time of equal day and night, in the Northern Hemisphere, occurring a few days before the vernal equinox). The Sun crosses the celestial equator going northward; it rises exactly due east and sets exactly due west. See our First Day of Spring page

Crocus field spring


On the summer solstice, we enjoy the most daylight of the calendar year. The Sun reaches its most northern point in the sky (in the Northern Hemisphere) at local noon. After this date, the days start getting “shorter,” i.e., the length of daylight starts to decrease. See our First Day of Summer page

Sunflower bees

Autumn (Fall)

On the autumnal equinox, day and night are each about 12 hours long (with the actual time of equal day and night, in the Northern Hemisphere, occurring a few days after the autumnal equinox). The Sun crosses the celestial equator going southward; it rises exactly due east and sets exactly due west. See our First Day of Fall page.

Fall leaves


The winter solstice is the “shortest day” of the year, meaning the least amount of sunlight. The Sun reaches its most southern point in the sky (in the Northern Hemisphere) at local noon. After this date, the days start getting “longer,” i.e., the amount of daylight begins to increase. See our First Day of Winter page.

Winter solstice

What’s your favorite season—and why? Let us know in the comments below!


Reader Comments

Leave a Comment

I love fall because the

I love fall because the leaves turn orange, I can wear my favorite sweater and boots, I can start drinking pumpkin spice lattes, the stores are filled with Christmas decorations, thanksgiving is near, because my birthday’s in November, and I can get to play with my pets outside longer without getting a tan haha

Favorite Season

I love autumn. It's always been my favorite season. First of all, I love Halloween. I always have. But I love the leaves falling and the cooling breeze. There's just something so magical about it. I've also loved horror movies since I was a teenager, and by the end of September, it just feels like it's that perfect time of year. (Although, for the last few years, September has been extremely hot. It seems like the seasons are a month off. Spring is April–June, Summer is July–September, Autumn is October–December, and Winter is January–March.) My next favorite season is winter. I love snow, and believe it or not I think there's something beautiful about the naked trees. Summer is third. I hate the heat, but early summer is the best because the trees have all their leaves again and things are full. I don't hate spring, but it is (by process of elimination) my least-favorite season. Too much pollen. At the beginning of spring, I'm missing winter, and by the end of spring, I want summer. So it's not spring's fault; it's just not the best (to me).

Favorite Season

I really like your description of the seasons. I feel similarly to what you've written.

Fall and Winter

Andrew, I too enjoy fall and winter for the exact same reasons as you have written. My German Shepherd girl Ruth is in agreement with our feeling for Fall and Winter as well.
The smell of wood burning in my wood stove and the glow if it's flame sets the mood of relaxing and the hope of a deep blanket of snow here on the mountain in SW Virginia.

Favorite season

Winter, for the shortest length of daylight. I prefer the cold + dark. Less work + maintenance to take care of outside, no gardens to clean up or weed, no grass to mow, only one application of spf needed on these shorter winter days. Plus I love my sweaters + fleece, my coats and winter hats, my wool things. I’m happiest inside looking out at a snowstorm.

Favorite season

Thanks Susan, I agree with you! The shorter "days" and longer nights remind me to make good use of daylight and appreciate the opportunity to enjoy the projects I didn't have time to do during days with lots of daylight. This is when I sew, cook my favorite hearty dishes (and freeze some for the busy days later) and clean some of the nooks and crannies that were neglected when I was outside during the summer and fall. Mostly it's a chance to slow down and enjoy those snowy days inside.

Favorite season

Where I live now in the mountains, I love Fall, because it's cooling, even though we don't get very many super hot days. In winter, I love more rain and the beauty of the snowy days and the cozy warmth inside..... I am 78, so, I don't get out in the snow except when necessary. I love the beautiful days of Spring when the trees and flowers are waking up and the cool days the windows can be opened to enjoy the scents of spring in the air. I love the wonderful four seasons I have enjoyed the past five years especially, because most of my life I lived in Bakersfield, can where there is only two seasons, coolish winter and early spring and late fall. And pretty much hellishl summers that last generally from May to mid October.

Seasons of Favor...

Love Spring, Summer and Winter equally. Those periods offer great diverse outdoor activity time here in Maine. Fall in New England is gorgeous for a while, but then presents way too much cleanup work to be completely enjoyable, until the snow arrives. The nature and short duration of each of my favorite seasons definitely pushes me to get as much out of each one and keeps me very active. I wouldn't have it any other way.

Spring! Late Winter, early

Spring! Late Winter, early Spring actually. By the Summer Solstice even though I hold onto my attitude of good weather until November.. and the Winter Solstice has its purpose and beauty, I always like the lengthening days rather than the shortening.

Earth needs a break

What a beautiful planet we live on and I agree with the comments on all the metals and pollution. Are group studies mule deer and were finding that are pollution and unpredictable weather patterns and science are killing the deer with polluted rains in streams and in soils. And is having a big affect on there breeding seasons. There something and a Idea a child said to.me the other day. She said why don't we stop businesses with drive thru.(walk in and takeout or dine in). She said think all the cars in a day that would be turned off not sitting idle and polluting our cities and less pollution, and also not to.mention most these places are not healthy to eat at anyway. Good idea young one. It's a start and everyone can do.

Good idea, take it one step further.

If everyone would ride a bicycle, the Earth would be cleaner and everyone would be healthier.

Good idea, take it one step further.

If everyone would ride a bicycle, the Earth would be cleaner and everyone would be healthier.

The Seasons

Pretty soon I am sad to say most of this science and predictions will not be accurate. These idiots keep spraying our skis with aluminum and heavy metals that cause everyone more health problems than they know but at the same time it changes the amount of sunlight we receive and make the rain come down more than it should. LOOK AT TEXAS !


Some predictions I disagree with and some, I not only agree with, but I embrace them as well. Global warming? GREAT!!! Since we are a couple thousand years overdue for an ice age, I say warm it up! :)
You are not real specific in your statement at all. (I'm kind of surprised I am even attempting to make a statement with regards to that which you wrote)....
Ok. Look at Texas? What? I live in Texas and I do not own skis for snow or for water. I know many people who have one, the other, or both. They have never mentioned anything about aluminum having been sprayed on their skis...
I decided a few years ago to only worry about myself and my own actions in this world. To waste time and energy worrying about things over which I have no control is not something I want to do any longer. As it turns out, I am much happier and more productive now.


I think he meant "Skies".... not ski's...
I've heard some rumor about fine aluminum sprayed at high altitude...
Why ? I have NO CLUE


FYI: Aluminum is not a "heavy metal". Its atomic number is 13, one of the lighter elements.
From Wikipedia: "By mass, aluminum makes up about 8% of the Earth's crust; it is the third most abundant element after oxygen and silicon and the most abundant metal in the crust. .....Despite its prevalence in the environment, no known form of life uses aluminium salts metabolically, but aluminium is well tolerated by plants and animals."
So...your assertion about it is incorrect.

Again.... Hmmm

You took the wrong turn a step further...
and gave it your own educated twist on a derailed subject.
Back on track,
Tell us why they are spraying Aluminum in the HIGH Altitudes ...?

The Seasons

While I understand the sentiment, it barely scratches the surface. Come on, how much have skis affected Texas? Really, the heavy metals are natural elements, hence they barely make an impact on our ecosystem. BUT, the way we process them definitely does. Our carbon footprint is what is truly affecting the environment. As long as there are measures in place to reduce (especially, but not limited to) carbon emissions, we can preserve our planet as much as possible. Then, there is Darwinism and survival of the fittest. Many species (though some do not) have and will adapt/evolve to the changes in our environment. Consider the Mesozoic era, when dinosaurs polluted the planet with unimaginable amounts of methane from their excrement—methane gas has 20x more effect of trapping atmospheric heat than carbon dioxide...and who would want to dance around piles of dung all day, anyway? Just try running cleanly through a cow pasture...or even the New York subway system! To contain and process waste, we must also produce waste. But, containment is a far lesser evil than the prior. Some countries/regions are even recycling feces, converting it into usable energy. We should embrace and appreciate scientific advancement for longer, overall better qualities of living while doing our best to respect the Earth. Oh, yeah...and treating others with the same consideration goes a long way, too. So, if someone says they feel they’re being treated like “sh!t,” you might respond with the aforementioned comment and let them know that, viewed in the right perspective, that isn’t necessarily such a bad thing!

P.S.—Having grown up a rural area in the Northeastern part of the U.S., I appreciate all four seasons and currently miss that aspect of life in the ever growing conurbation of California (not unlike the megalopolis of the northeast seashore from Boston to Washington). At least the east coast gets the seasonal experience, though not as spectacular as Appalachia or even the Great Lakes Megapolitan region. That being said, the American Southwest and Pacific Northwest are equally spectacular in their own rights. Having traveled around and about five continents, I’ve never been disappointed. Really, beauty can be found just about anywhere, so long as one is ready, willing, and able to perceive it.

Favorite Season

I Love the 15 plus hours of possible sunshine
All that Sunshine and Vitamin D
It just makes me feel so glad to be alive
The Hotter The better


Howdy -- Again -- Farmer's Almanac,
Again: Thank You For Your Great Work Over These Decades!
===> Please Note That I Was Wrong! <===
It Must Be That Your Diagram Is -- Right --, Because:
In The Northern Hemisphere The Path Of The Sun Is High In The Sky During The Summer And Low In The Sky In The Winter.
Please Accept My Apology For My Mistake.
Possibly, the Earth might be actually closer to the sun distance-wise in the Northern Hemisphere's Winter, and farther from the Sun in the Northern Hemisphere's Summer. I am Not Sure About This!
Thanks & God Bless All!
Gary Internet Participant

seasonal changes

The Editors's picture

Thank you for your well wishes!

As you discovered, the diagram is correct, even though it would seem that it should be the opposite. Our closest position to the Sun for the year was in January (called perihelion); it is farthest away in July (aphelion). But it’s not the proximity of Earth to the Sun but the angle of the Sun’s rays that create the seasons. In winter, the angle of the Sun’s rays is low in the Northern Hemisphere, so the Sun’s energy is distributed over a larger area, weakening its intensity in any one place (sort of like the light from a tilted flashlight falling on a ball); the days are also shorter than they are in summertime, so that we receive less energy from the Sun.

At the spring and fall equinoxes, we are neither tilted toward nor away from the Sun, which means that at the Equator, the Sun’s rays are coming in at about a 90 degree angle—so the energy there is concentrated along a smaller surface. However, at the higher latitudes, such North America, the Sun’s rays are still being received at more of an angle, so we’re getting less intense rays than the Equator, and things are still a bit cool. As the spring days progress toward the summer solstice, the angle of the Sun’s rays become more direct, and the days are also getting longer, which increases the amount of energy that we are receiving. So, we’re getting more energy as spring progresses, resulting in warmer temperatures. Meanwhile the ground and water are absorbing this energy and releasing it. Water can hold more than earth, but in both cases, it takes a while before they can warm up enough so that they are receiving as much energy as they release, so that we feel the warmer temperatures. The most direct sunlight that we receive occurs at the summer solstice, which is also the longest day, but again, the full effect temperature-wise won’t occur until a little later. Eventually, though, the loss of heat will overtake the amount of heat the Earth receives, because of the decreasing angle of sunlight and the decreasing day length as Earth approaches the fall equinox and then the winter solstice. Then the cycle begins anew.

Hope this helps!


Howdy -- Again -- Almanac,
Again: Thank You For Your Great Work Over These Decades!
Please Note That I Was Wrong!
It Must Be that your Diagram Is Right, Because The Path Of The Sun Is High In The Sky During The Summer And Low In The Sky In The Winter
===> Beautiful Diagram Of "Why Do The Seasons Change?" Has An Error:

Beautiful Diagram Of "Why Do The Seasons Change?" Has An Error

Howdy Almanac,
Thank You For Your Great Work Over These Decades!
===> Beautiful Diagram Of "Why Do The Seasons Change?" Has An Error:
At the Winter and Summer Solstices, the tilt of the Earth is backwards. In the Northern Hemisphere, the Earth is tilted toward the Sun and is tilted away from the Sun in the Summer. This is why the seasons are somewhat milder in the Northern Hemispheere.
The Solution is to simply reverse the words 'Winter" and 'Summer" and to reverse the words "Vernal" and "Autumnal".
Please, verify that I am right before changing the diagram, and please, do not just disregard what I am sharing here. Please, remember, The Farmer's Almanac has a wonderful record and reputation of being honest and as accurate as possible.
Thank You and God Bless All,
Genesis 01:31
Gary Internet Participant

Thank You

for your informative and entertaining site.....as I (attempt) to make the transition from traditional religions, mainly Roman Catholic, I find this (your site) to be quite comforting.....♥

Wrong time zones

GMT - what's all this Yank rubbish? If summer starts on 21/6 (day/month/year - logical format) just after midnight, that means it actually starts on 20/6 GMT (GMT where time is actually measured from). 0/5!

Correction, you confused me.

Correction, you confused me. Summer '17 starts:
(June Solstice/Start of smmer) Worcester, England, United Kingdom is on
Wednesday, 21 June 2017, 05:24.
However - 'June Solstice' is the 'longest' day, of sunshine (still 24 hours). This means that you're getting less sunshine each day as summer progresses! Maybe we should just use Calendar Seasons: Summer = June/July/August, etc. Which pushes the Summer Soltice a bit closer to the middle of summer, instead of right at the start, which makes more sense.

Goat, You're Turned Around

When it's 12:24 a.m. in New York (EDT), it's 04:24 a.m. in London (GMT) on the same day. It's the previous day in westward time zones.

Regarding the date structure, remember that the Farmer's Almanac is an American publication and, thus, supports American usage. I'm not saying it's correct. It's just the way dates are abbreviated here.


Traditional festivals, wear garlands of flowers

time zones

how do I subtract 3 to what I am confused on that from what to what I do not understand it at all.

greg Jackson

Subtract three hours to the

Subtract three hours to the time if you are in the Pacific time zone.