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

Favorite Season

Spring! Everything comes alive again! The sweet little crocus coming up in the warm sun, even threw a coating of snow! Mtge snow drops! The maples budding with the promise of new leaves and cover for my chickens, lovingly known as “the Peepers”! The pink dogwood that always blooms for Mother’s Day, and the Lily of the Valley that always blooms for my daughters’ birthday! Followed by the May blooming Iris!
What’s not to love about spring???

Favorite Season

I love summer! I'm out of school and I am carefree and summer is full of fun and trips to take. I get to spend all day with family and friends. It is warm all day long and I can go out early and it won't be cold. Spring is also great too.


What's not to love about Spring? How about too much rain, spring is wet and mucky most of the season.

Length of seasons

When looking at the dates for the astronomical seasons I found it odd that spring and summer are 93 days and fall and winter are 89 days. I wonder why that is. My initial thinking is the length of days would be the same except for leap year.

Why The Seasons Are Different Lengths

The Editors's picture

That’s a good observation! The difference in the lengths of our seasons stems from the shape of Earth’s orbit around the Sun. Because our orbit is an ellipsis, Earth does not stay the same distance away from the Sun for the whole year; we reach our closest point to the Sun (perihelion) in January and our farthest point (aphelion) in July. Read more about this phenomenon here.

Thanks to the pull of gravity, objects travel slightly faster in their orbits when they’re closer to the object they’re orbiting. For those of us in the Northern Hemisphere, this results in winter being the shortest season—we are literally 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 long summer. (These are reversed in the Southern Hemisphere.)

If our orbit was a perfect circle and we always remained the same distance from the Sun, then our seasons would be almost identical in length. 

Favorite season

Winter. I prefer the darkness. I like shorter hours of daylight.


You prefer the darkness? Most people find winter depressing because of so much darkness, and don't care for eating dinner at 5:00pm in the dark. Winter is so cold and desolate......burrrrrrr


My favorite season is Summer. The reason I like this season is because it's warm and my birthday is July 2nd. I also like Summer because it is a nice season to be outside and to go places.


My favorite time of the seasons is FALL. We witness the beauty of leaf colors especially in Deep East Texas.


I used to live in Texas but I moved because of the hot, hot Summer's.

winter begins

is miss printed as dec. 21,2018 11:someting pm in the paper back sold form 2018 / 2019. is there more wrong info?

don;t no with to plant i at this time of the year

can you tell me what i can put in the grand i am in FL zip is 32428

Things to plant during winter

You can plant onions, shallots, garlic, peas, and radishes during the winter. There are other things but these are just the ones in my knowledge.

Favorite season

Spring is my favorite season. It signals the start of new growth.
Autumn is my next. I LOVE the colors fall brings to the landscape.

Favorite season

Fall is by far my favorite season. We live on the side of a mountain where the colors are spectacular and I also prefer the cooler temps. I also do love winter and spring, I enjoy the snow and the Christmas season in winter and the renewal of life in the spring. I only tolerate summer because I grow a large vegetable garden, if not for that I would be just fine with no summer at all.

On the side of a mountain

The Editors's picture

It sounds lovely, Monte. Thank you for sharing this impression. As for summer…be careful what you wish for! We think you just might miss that veg garden if there was no summer at all. (We sure would miss our veg gardens!)

Favorite Season

I love summer. Long, pretty days, short pleasant nights. All of nature’s beauty on display. Being outdoors without having to add 10 pounds of clothing, to me, is as close to being “with nature” as it gets. I envy those who live in places like Hawaii where it’s warm all year. And I never get tired of bright blue skies and bright green grass and foliage. Oh, and palm trees!

Challenging the “beginning” of the seasons

The seasons are determined by the amount of light or darkness. The tipping points, if you will... the first day of spring is not the vernal equinox, as that is the day of equal light and dark; the first day that has more light than dark is typically February 2nd, or Imbolc, then equinox, May 1st is the first day of Summer, and the Solstice is the height of Summer (longest day) think ... mid summer’s night dream... then the first day of autumn is opposite February 2nd, August 3d Lammas, next is the autumn equinox, half way between equinox and height of winter (longest night), we have October 31 and November 1st, Halloween, day of the dead: official first day of winter.

Season starts

That is a good answer. Seasons have little to do with equinoxes. Since early times the life in the Northern hemisphere was governed by
agriculture. Planting (Spring, Feb-Apr), Growing (Summer, May-July), Harvesting (Autumn, Fall, Aug-Oct) and Fallow (Winter , Nov-Jan),
which essentially follow weather and light. Ist of May (Mayday) is celebrated as the beginning of summer and June 21 as Midsummer Day.
(Oxford Dictionary)
Statistical weather data can be accumulated for any grouping of days or months without confusing historically designated season names.

Favorite season

My favorite season is Fall. It’s neither hot nor cold. Its absolutely BEAUTIFUL. MY husband has been a trucker for over 20 years. I have ridden with him for most of that time. We have been all over the U.S. Have seen the seasons change everywhere. I LOVE THE HIGHWAY STILL and I LOVE THE CHANGING OF THE SEASONS. I like It neither too hot nor too cold is why I prefer Fall. I really like Spring also, but I can’t stand the summer heat which will soon come is why Fall is my FAVORITE.


As it happens, Australia observes the meteorological start dates to the seasons (for the southern hemisphere). Some indigenous cultures had identified six seasons based on climate, but by Canadian standards, winter doesn't really exist in Australia except in a few mountainous areas. A fair part of the continent is closer to the equator than Houston is.

Nice article and graphics.

Nice article and graphics.

I am wondering why the top image shows the seasons in a counter-clockwise rotation. Does it have to do with an old-world calendar or some other tradition?

Great article.

Seasons Image

The Editors's picture

I’m afraid the answer is not so mysterious: the image is a stock photo, so whoever created it just decided to lay out the seasons in that way!

Seasons Image

The graphic depicts this counter-clockwise direction because the earth rotates on its axis in a counter-clockwise direction and also orbits the sun in a counter-clockwise direction.

rotation of celestial objects

It seems to me the earth rotates on its axis in a counter-clockwise direction if the north of axis is on "top". Yet, If viewing with south axis "up vertical"/"top", earth rotates clockwise. Does the our star the sun have a poles? Which way are our poles positioned in RELATION to sun's poles? Likewise for directions and positions of our sun's system. What relative objectivity do we apply to our galaxy? Is there a humanly established objective for the directions and positions in our universe?

favorite season

my favorite season is summer because schools out and i get to ride my bike and i like it


If the current day is not a spectacular example of whatever season it currently is, I tend to remember all other seasons with fondness.

Favorite season

The love of autumn fall great cool days.

Favorite season

I was born and raised in the San Francisco bay area where we have two seasons...dry and wet. I moved to central Pennsylvania two years ago where, of course, there are four distinct seasons. I find I love all of them! Spring is spectacular after the long winter. The greens are so vibrant and the colors of the blossoms really stand out against the new green. Summer is lush. In California, the grass on the bay area hills turns brown by early May and stay that way until it starts to rain, hopefully, by October. So, to have a lush, green summer is something very new to me. However, I can't stand the humidity! Autumn is the best. It has always been my favorite season, but in California, could only experience it in very small bits. There is some foliage, but nothing like what I've experienced here. And winter...it's cold, but the beauty of the snow makes up for it. I finally have that white Christmas. Winters can be long...we had snow on April 17 of this year (2018) and I was not amused. But the beautiful Spring more than made up for it!

Favorite season

They’re all my favorite! Being they have there own unique beauty. Starting with winter. How you look above you and see thousands & thousands of sparkles in the night sky. Plus the same amount of sparkles below you. From the snow covered ground or the iced over trees. Then how a lot of people decorate for the good lords birthday. Lights lights lights.
Then there’s spring, when the earth thaws and pretty colorful fragrance flowers emerge from the ground and blooming trees. Where you hear the birds singing their songs.
Summer is all about the warm weather. Be able to enjoy the outdoors with family & friends at gatherings at the lakes, parks, any place there’s a celebration. Seems the time people get together more.
Awe. Fall. How you can watch the earth color itself in just vibrate bright beautiful colors. Seeing the greens dull as the trees reflect just gorgeous yellows, reds, oranges. So peaceful to enjoy that beautiful on a walk in the woods. Before the leaves turn brown to make your own music as you walk on them and they crunch. From their dryness Can’t forget jumping in the leaf pile.
All four seasons are just fabulous.