When Do the Seasons Start in 2020?

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

June 10, 2020
Spring, Summer, Fall, Winter 360

When do all of the four seasons—spring, summer, fall, and winter—start and end? Here are 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.

Spring

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

Summer

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

Winter

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

But, really, none of the

But, really, none of the calendar dates for what we call the seasons is associated with any kind of sudden temperature change. At the Autumnal equinox, maple leaves don't suddenly turn red. We basically move gradually between warm weather to cool weather to back again over and over. The idea of four separate, distinct seasons is really related more to social customs and human activity like agriculture (for planting, growing, harvesting and fallow times) isn't it?

The dates for the beginning

The dates for the beginning and end of months are based on the Gregorian calandar. If you go further back to the more pagan calandars, you'll find that the dates that are currently used for beginning/end of the seasons were actually the middle.

The beginnings were Samhain (October 31), Imbolc (February 2), Beltane (May 1), and Lughnasadh [Lammas Day] are the beginning.

The middle of the seasons are Yule/[Christmas], Ostara[Easter], Midsummer, and Mabon[Mid-Autumn]

Thank you Marie Mayer for

Thank you Marie Mayer for being an intelligent person.

I agree with Kera, thank you

I agree with Kera, thank you for being an intelligent person! We Celebrate the pagan holidays and season changes because they're all nature based and not religion based.

I'll say it too, thank you

I'll say it too, thank you Marie Mayer!

You're spot on. Somebody told

You're spot on. Somebody told me that 21st June is the first day of Summer. I said, "Where?" They replied, "Everywhere!" I think Australians would beg to differ! But it got me thinking. Taking into account all the astronomical, geographical, longitudinal, latitudinal,oceanic, climatic and meteorological variables, every day must be the first day of summer somewhere in the World? Strange how easy it is for most people in the World to believe that the exact opposite is true? I think that might be 3 cents worth. Sorry!

My thoughts exactly - why is

My thoughts exactly - why is the summer or winter solstice the Beginning of that season? Shouldn't it mark the mid-point? How can it be that Winter in the S Hemisphere starts on the 21 June Winter Solstice when immediately after that point the days start getting longer? Doesn't make sense to me.

It is long overdue to do away

It is long overdue to do away with the counting of time on the basis of the Holy Roman Empire Anno 2013. With all the high tech, instant coffee and archeological findings the Collective Mind still is bullied by religions spearheaded by the Vatican. It would be a great advancement for our grandkids when the Collective Mind would show higher awareness and determine a point of substance on which basis to count time instead of the Holy Roman Empire. Quadriphasic keeps you on your toes for harvesting.

THANK YOU!!!!!! that is

THANK YOU!!!!!! that is all....

I'm a little confused -- when

I'm a little confused -- when you refer to the Holy Roman Empire, do you actually mean the Roman Catholic Church? Those are two completely different things.

Today is the Winter Solstice in the North Hemisphere. It's been winter for a few weeks here, but it's a typical Georgia winter; we may get a record high of 75 F today. I miss snow.

There is a great site that

There is a great site that details the actual progress of the seasons as based on the quarters and cross-quarters: http://www.archaeoastronomy.com/ - it also provides an animated star clock that shows where we currently are in the orbit of the earth as of today and the tilt of the earth as it progresses through the orbital cusp point. Also, it was earlier mentioned that the tilt of the earth's axis is 23.5 degrees - that is incorrect - the current tilt of the earth's axis (as of mid-2013) is 23.439 degrees. The tilt of the earth's axis is affected by many factors, some regular and predictable (related to the precession of the equinoctes and the effecct of lunar gravity) and others unpredicatble (e.g. redistribution of mass due to earthquakes) - for instance, the great earthquakes of 2004 in the Indian Ocean basin and in 2011 at Japan in the Pacific Ocean basin actually slightly affected the tilt of the earth by moving larges masses of the Earth's material closer to the centre of the Earth. The Earth's axial tilt is currently decreasing, and may vary between 22.1 and 24.5 degrees. It is postulated that when the Earth's tilt is at the maximum point of 24.5 degrees is when ice ages typically occur - and as well, ice ages also have an effect on the axial tilt, since they redistribute large amounts of mass (i.e., ice) towards the geographic poles. The after-affect of this mass redistribution is still being felt due to crustal rebound of areas of the Earth that were under massive volumes of ice during the most recent ice age (for instance, the Hudson Bay basin in Canada is currently rebounding by close to 2cm per annum due to the removal of the Laurentian ice sheet following this most recent period of global climate warming [unrelated, BTW, to any human-induced warming of the climate]).

Thank you so much for the

Thank you so much for the educated answer on the tilt of the earth. I knew the earth changed it axis recently but did not know it was linked to major earthquakes. I will be visiting the website you suggested. Great explanation. I too live 'downunder' and yes our date for the beginning of seasons is different to the north. Does anyone know the history of this fact?

Are there different first

Are there different first days of seasons in different countries? Im doing a report and can't answer what date spring starts in Greece.

The astronomical definition

The Editors's picture

The astronomical definition of when a season begins (such as the March equinox: spring in the Northern hemisphere; fall in the southern) applies everywhere around the world (a set point in time, converted to local time zone).

However, different countries may celebrate the seasons at different times. For example, in Bulgaria, March 1 is often celebrated as the beginning of spring. Also on March 1, Helidonismata is a traditional Greek observance that celebrates the return of the swallows, marking spring's return, as well.

You might also be interested in Greek mythology as it relates to spring: the story of Demeter and Persephone.

In Russia winter officially

In Russia winter officially starts on 1 of Jan, spring on 1 of March, summer - on 1 of June and Autumn on 1 of September.

the references to 'the

the references to 'the longest day' and the 'shortest day' is in error. Each day of the year consists of 24 hours--it's the length of daylight hours that varies! I recommend you change the word day to daylight in order to be accurate.

Actually, To call a day

Actually, To call a day exactly 24 hours is incorrect in every regard except the one on people's wrists (that is to say, the times when we arbitrarily assign tasks so everyone has a medium of understanding.) Also, the day varies by several seconds from thousands of subtle variables (including the earth's distance from the sun.)

Ted, there are various

Ted, there are various meanings of the word 'day'. Day and night are often used as opposites.

Ted, we made some revisions

The Editors's picture

Ted, we made some revisions to make it clear that we are referencing the amount of daylight in a calendar day. Thanks.

Due east at the equator.

Due east at the equator. It's always slightly south (or more) north of the tropic of cancer in the northern hemisphere.

Used to love the

Used to love the Almanac...but it got too full of ad nonsense and yuppie eco-fashionista fluff pieces. I prefer my favorite small town cafe for the real news of the seasons.

The Old Farmer's Almanac has

The Editors's picture

The Old Farmer's Almanac has not really changed in over 220 years. Hope you will check it out again and see that it is remarkably similar from cover to calendar pages.

I agree, the Old Farmer's

I agree, the Old Farmer's Almanac has maintained a consistent style throughout it's many decades of publication, and it is an indispensible tool for those of us who prefer to plant by the Moon, just as crucial as any hoe or sickle. (I only wish they'd correct the mis-naming of Summer and Winter Solstices as the beginning of those respective seasons-- they actually fall in the middle of them.)

does every season being on

does every season being on every full moon

No. As mentioned in the

The Editors's picture

No. As mentioned in the article above, the first day of the season is determined by how our planet orbits the Sun and the tilt of its axis.

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.
Regards,
Paul

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?

Pages