When Do the Seasons Start in 2019-2020?

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

September 16, 2019
Spring, Summer, Fall, Winter 360

When do the four seasons—autumn, winter, spring, and summer—start? Here are your equinox and solstice dates for 2019 and 2020—plus, the definition of the astronomical season versus the 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

Note: These 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.

Seasons of 2019 Astronomical Start Meteorological Start
SPRING Wednesday, March 20, 5:58 P.M. EDT Friday, March 1
SUMMER Friday, June 21, 11:54 A.M. EDT Saturday, June 1
FALL Monday, September 23, 3:50 A.M. EDT Sunday, September 1
WINTER Saturday, December 21, 11:19 P.M. EST Sunday, December 1
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

Astronomical Season vs. Meteorological Season

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. However, we have listed both dates for each season above.

Why Do the Seasons Change?

We have the four seasons because of shifting sunlight (not temperature!)—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, 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 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

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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

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...

yug...

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

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. :)

Happy Autumnal Equinox 2011.

Happy Autumnal Equinox 2011. After Spring, Fall is my fave time of year. Love the smell of the fresh air as the temps change.

Love the Almanac ,too. From the time I was about 13 my Mom always made sure Santa put a copy of the Almanac in my Xmas stocking. Always something interesting to learn. Since my parents have moved on to the 'next realm' I make sure to get myself an Almanac for Xmas every year. It gets picked up by everyone that stops by over the holidays.

I always look at the almanac

I always look at the almanac to help me figure out when I'm going to plant my vegetable garden each year. It is something that my grandmother taught me to do to get the most out of the gardening season. I've even planted my vegetables in pots before the season starts so that I can transplant them outside and get a head start.

The Almanac sits near our

The Almanac sits near our couch and is viewed often and by many... Thanks So Much

I love the Almanac, too. It

I love the Almanac, too. It is full of interesting and very important information. Thanks, Kimberley

There is so much to learn

There is so much to learn from studying the past. Washington is no match for Mother Nature.

I love the Almanac

I love the Almanac

My Mother used to get these

My Mother used to get these same exact Almanac's back in the day...it's sooo beautiful making this connection. KEEP READING this stuff...I love you...by Deremiah *CPE

What would we do without

What would we do without it?
I for one would be lost

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