When Do the Seasons Start in 2020?

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

August 26, 2020
Spring, Summer, Fall, Winter 360

When do all of the four seasons—fall, winter, spring, and summer—start and end? Find your equinox and solstice dates for 2020 and 2021—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 2020 Astronomical Start Meteorological Start
SPRING Thursday, March 19, 11:50 P.M. EDT Sunday, March 1
SUMMER Saturday, June 20, 5:44 P.M. EDT Monday, June 1
FALL Tuesday, September 22, 9:31 A.M. EDT Tuesday, September 1
WINTER Monday, December 21, 5:02 A.M. EST Tuesday, December 1
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, 3:20 P.M. EDT Wednesday, September 1
WINTER Tuesday, December 21, 10:58 A.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

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Is Dec. 21, 2012 the first

Is Dec. 21, 2012 the first day of winter 2012 or the first day of winter 2013? Didn't we go through the winter of 2012 back in January of this year? So on March 20th, 2013 (the first day of Spring 2013) will we have just finished the winter of 2012 or the winter of 2013? Please clarify.

As you've noticed, the winter

The Editors's picture

As you've noticed, the winter season spans the end of one year and the beginning of the next in the Gregorian calendar. December 21, 2012, at 6:12 am EST starts the first day of winter 2012/2013 (often just listed as winter 2012). Winter 2013/2014 (winter 2013) would begin on December 21, 2013, at 12:11 pm EST.

In astronomy, each year in the Northern Hemisphere can be defined as beginning with the spring (vernal) equinox in March. The summer solstice occurs in June, the autumnal equinox in September, and the winter solstice in December. Astronomically speaking, in the Northern Hemisphere, the winter solstice is defined as when the Sun reaches its greatest declination (23-1/2 degrees) south of the celestial equator, around December 21. So, winter 2012 marks the time when the first day of winter begins for 2012/2013. It's the time when the Sun reaches its southernmost declination for the year 2012.

If December 21st is the first

If December 21st is the first day of Winter, why has it been referred to as Midwinter through the centuries? Is December 21st (or 20th, as it varies) not the point in time when the days are the shortest, with the next day being the time when the days begin to lengthen? And would this not, in turn, dictate that Winter proper actually begins in November? Would it not have to follow that Midsummer/Summer Solstice marks the high point of the Sun's energy and, after this, the shortening of our annual cycle of daylight hours through until the Midwinter/Winter Solstice, when the days begin to lengthen once again? If so, how could the Summer Solstice possibly be the beginning of Summer or the Winter Solstice possibly be the beginning of Winter?

The Celts divided the year into two major halves, Winter and Summer, with the cross-quarter events being the Spring Equinox and the Autumnal Equinox. The year began on November 1st, the beginning of Winter. Midwinter was genuinely the middle of Winter, ending on the Spring Equinox as Winter began to wane and the foliage bloomed. Summer officially began on May 1st, as by this time the growing season was in full swing, with the last vestiges of the Winter season behind us. Midsummer, the longest day, was the beginning of the waning cycle, as Summer began to move toward Winter. The Autumnal Equinox (generally the approximate harvest time) marked the manifestation of the seasonal changes preceeding Winter's arrival, again on November 1st. Since agriculture was the dominant industry, this reflected the agrarian/astronomical calendar cycle, which was the basis for our modern calendars.

I've addressed this before, and am still perplexed as to why anyone would insist on referring to the Winter and Summer solstices as the beginning of their respective seasons, when they clearly are not at all.

These MID-Summer and MID-Winter designations are the correct astronimical divisions of the year, as they are based on the actual effect of the solar cycle on the Earth's seasons.

I realise there are all these newer ideologies and theories on when the seasons begin and end (meteorlogical, temperature and regional variances, etc.), but the fact remains that Midsummer and Midwinter are precisely that-- the middle of these seasons, and not by any means the beginning. (Unless, of course, the Sun is wrong in his astronomical movements, and if so someone had better inform him.)

Yes, the definition of when a

The Editors's picture

Yes, the definition of when a season begins can vary between countries, cultures, organizations, and individuals. For example, the ancient Celts considered equinoxes and solstices (called quarter days) as the midway points of the seasons. Their cross-quarter days (halfway between quarter days) were the beginning of the seasons. Astronomically speaking, however, the seasons begin at the equinoxes and solstices, which define four unique points along Earth’s orbit, in which the Northern or Southern Hemisphere tilts toward the Sun (summer), away from the Sun (winter), or is neutral--neither leaning toward nor away from the Sun (spring, autumn).

An astronomical definition does not directly take into account what is going on within Earth’s atmosphere. Other definitions focus on how the Sun’s intensity (energy) or heat affects the surface. A meteorological definition of seasons, for example, often is based on temperature. An international meteorological definition separates the year into groups of three months: March 1 is the beginning of spring; June 1 starts summer; September 1, autumn; and December 1, winter. However, days of greatest warmth and cold (on average), or length of season, can vary by region depending on their proximity to water, latitude, prevailing winds, etc.

Other seasonal definitions take into account annual responses by plants and animals. Or, define the seasons according to religious or cultural criteria.

For The Old Farmer’s Almanac, because we are a calendar of the heavens, we officially use the astronomical definition. But, we certainly agree that there is more than one way to define when the seasons begin.

Okay, I'm confused. Your

Okay, I'm confused. Your chart stated that the winter solstice begins at 6:03 p.m. EST, but above you say it's 12:11 EST. Which is correct? Am I missing something?

Hello, Old Gardener, Both are

The Editors's picture

Hello, Old Gardener, Both are correct. There are two different years referenced. For the 21st of December 2013, winter begins at 12:11 pm EST.

Thanks for the information we

Thanks for the information we studied most of this in geography years ago ..but its a good reminder and people should know that it varies in different parts of the world on their standard time. Although it shows spring in many parts the snow is still there but U may see tiny shoots coming up sooner or later.

Dear OFA...How do I love

Dear OFA...How do I love thee? In many countless ways! Keep on keeping on!

Aww. Shucks. We appreciate

The Editors's picture

Aww. Shucks. We appreciate the kind words. Your obedient servant, The Old Farmer's Almanac

Great Website. 09/17/2012,

Great Website.

09/17/2012, Monday

I initially visited this website in order to determine the exact date and time of The Autumnal Equinox, and The Winter Solstice for 2012, which [according to the valuable information available here] is 09/22/2012, Saturday and 12/21/2012, Friday. While I was here I read some other very interesting information also. This is great website with wonderful resources. Thank you. Dr. Stone / Tampa, Florida, United States.

Is this winter nit the end of

Is this winter nit the end of the Mayan Calender as we understand it. I was told it is the precise moment that all the planets will allign in a strait line for the first time in many centuries. the dawn of a new era as it seems. will be interesting to see if it is really just another y2k

Hi, Big Bill, It's a myth.

The Editors's picture

Hi, Big Bill, It's a myth. See more in our free Almanac Companion enewsletter here: http://us1.campaign-archive2.c...

Here is an excellent article

Here is an excellent article showing some Christian and Jewish traditions that revolve around the summer solstice. http://www.examiner.com/articl...

I have been waiting for

I have been waiting for 2012-12-21 for 40 years. I didn't even know if I would still be here. Now just 180 days.......... I don't think anything will happen, but I will be up before the Chicken. Just in case. LOL

There are several

The Editors's picture

There are several interpretations as to when each season begins.
In North America, calendars commonly use the astronomical definition. It is true that various countries, cultures, religions, organizations, and individuals may use definitions other than the astronomical. Because we are an almanac that provides astronomical data, however, that’s why we use the astronomical definition. For our weather predictions, however, we start with a more meteorological definition by providing Nov-March “winter” predictions, Apr-May for spring, June-Aug for summer and Sept/Oct for fall. Hope this is helpful. --Your OFA editors

I am afraid that I must agree

I am afraid that I must agree with Jonathan. It is not simply "various countries, cultures, religions. . ." that define seasons in a variety of ways, but more so different latitudes. The so-called "astronomical" dates might seem to be more objective and authoritative, but in defining seasons as phenomena that occur uniformly across an entire hemisphere, we ignore the curvature of the earth and the tremendous variation in climate that occurs between the equator and the poles. The astronomical dates might make sense for someone living on the moon and seeing the earth as a flat disc, but for those of us living on the surface of the earth, seasons start and end at a variety of times. I think that the OFA should resist the popular compulsion to have "official" dates for the seasons and instead accept the more scientifically and historically accurate definition of seasons as annual changes in levels of sunlight, temperature, and precipitation that vary according to latitude and climate.

I am sorry but your

I am sorry but your contention that the first day of spring is the equinox, the first day of summer the solstice, etc., simply is not true. The so called beginning of summer (the summer solstice around June 21st) and the end (the equinox around Sept 21 or 22) is merely the astronomical beginning and end of summer, nothing more nothing less. The meteorological beginning and end of summer is June 1st and August 31st respectively. I, and I think most people, tend to consider the meteorological time to be more accurate. Contrary to popular belief there is no official beginning and end of the seasons. No scientific or governmental body has ever formally bestowed such a designation. Again, June 21 or 22 to Sept. 21 or 22 (or Sep. 21 to Dec. 21 for Fall, etc.) are merely the astronomical beginning and end of summer it is not the "official" beginning or ending. For more information go here:

Is it true that you can

Is it true that you can balance an egg during the spring equinox ??

Yes, it is true and I did it.

Yes, it is true and I did it. I am trying to post one of the photos I took but haven't had any luck yet. If anyone knows how to post a JPEG here please adda acomment with the methodology.

Thank you for this great

Thank you for this great info! Spring is my fav season. Even wrote a paper on Spring when I had to take English Comp (tested out of it 40 years ago as a college freshman) in the late 90s as a prereq to getting my RN degree. Love "The Farmer's Almanac," and grew up with it always on the shelf next to the phone back in the day. Thanks bunches!

On Mar 17th the sunrise and

On Mar 17th the sunrise and sunset will be exactly 12 hours apart..so how do they come up with the 20th?

Great question. You are

The Editors's picture

Great question. You are correct. The "equal" night/day usually comes a few days before the equinox. Our former astronomer, George Greenstein, had this to say: "There are two reasons. First, light rays from the Sun are bent by the Earth's atmosphere. (This is why the Sun appears squashed when it sets.) They are bent in such a way that we are actually able to see the Sun before it rises and after it sets. The second reason is that daytime begins the moment any part of the Sun is over the horizon, and it is not over until the last part of the Sun has set. If the Sun were to shrink to a starlike point and we lived in a world without air, the spring and fall equinoxes would truly have ‘equal nights.’”

I have a fairly simple

I have a fairly simple question.
Does the winter solstice in the Northern hemisphere occur at the same time as the summer solstice in the Southern hemisphere?
If there is a lag in the exact time, is that lag due to the "wobble" of the Earth on it's axis?
Enquiring minds wander...


A good question. Perhaps some

A good question. Perhaps some Australians can help

It would appear that the

It would appear that the Solstice occurs this year on both the 21st and the 22nd -- depending on your time zone -- am I wrong?

Hi All,   It is my

Heidi Stonehill's picture

Hi All,
It is my understanding that the winter solstice in the Northern Hemisphere and the summer solstice in the Southern Hemisphere occur at the same point in time. However, local time, due to time zones, will vary. At the December solstice, Earth reaches a spot in its orbit such that its northern axis points the farthest away from the Sun (Earth's axis is tilted 23.5 degrees away from an upright position). The timing of this event is not dependent on where you are on Earth (such as a sunrise would be). However, the local time will change. Astronomers often list these events in Universal Time (UT), which is tied in to the time at Greenwich, England (0 degree longitude). From there, we need to convert to our local time.
Sometimes, the seasons occur near midnight. Therefore, as the event gets translated into local time, it may occur on one of two days (late evening of one day or early morning of the next day). This situation is happening for the December solstice in 2011. In Universal Time, the December solstice occurs on December 22 at the 5th hour 30th minute. In Eastern Standard Time, this is 12:30 am on December 22. However, in Central Time, this is December 21 at 11:30 pm; Mountain Standard is December 21 at 10:30 pm; Pacific Standard is December 21 at 9:30 pm, etc.
Hope this helps!
Heidi Stonehill
The Old Farmer's Almanac

After reading this I, of

After reading this I, of course understand the time zones, but it seems the season change may be at the same time all over the US? or does it come one hour after the previous time zone? In example Spring at 0700 EDT is also at 0700 CST?

Thanks Heidi!

Thanks Heidi!

Thanks Heidi your explanation

Thanks Heidi your explanation is informative.

Yes, both solstices occur at

Yes, both solstices occur at the same time. The northern axis points towards the Earth, creating more exposure, summer. On the directly oppisite side of the world, the southern hemisphere is in winter, because the southern axis is pointed away from the sun, becoming less exposed to sunlight. Both are solstises because the sun is either facing the Northern or Southern hemisphere, not the equator, which results in equinox. :)