Changing of the season

Changing seasons | National Oceanic and Atmospheric Administration

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In many parts of the United States, you might change your wardrobe with the seasons, grabbing a heavy coat in winter, while wearing only a light t-shirt in summer. Although ecosystems, plants, and animals cannot adjust their attire quite so easily, they have evolved to make changes that help them survive seasonal conditions caused by the rotation of the Earth around the sun.

Do you know the difference between meteorological and astronomical seasons? Astronomical seasons are based on the position of the Earth in relation to the sun, whereas meteorological seasons are based on the annual temperature cycle. The Earth’s annual trip around the sun forms the basis for the astronomical calendar in which seasons are defined by two solstices and two equinoxes. The Earth is tilted 23.5 degrees on its axis of rotation, and how the North Pole is oriented toward or away from the sun determines two of these astronomical dates. At the winter solstice, the North Pole is tilted away from the sun, whereas at the summer solstice, the North Pole is tilted toward the sun. The equinoxes occur halfway between these events when the sun’s path is aligned with the Earth’s equator. The dates shown describe the astronomical seasons for the Northern Hemisphere in 2022; the exact dates vary slightly from year to year. Meteorological seasons are broken down into groupings of three months in our civil calendar based on the annual temperature cycle. We generally think of winter as the coldest time of the year and summer as the warmest time of the year, with spring and fall being the transition seasons. In the Southern Hemisphere, the seasons are reversed where summer occurs when the South Pole is oriented towards the sun, and winter happens when the South Pole faces away. (NOAA Office of Education/Kaleigh Ballantine)

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Click to see this graphic for the Southern Hemisphere

Do you know the difference between meteorological and astronomical seasons? Astronomical seasons are based on the position of the Earth in relation to the sun, whereas meteorological seasons are based on the annual temperature cycle. The Earth’s annual trip around the sun forms the basis for the astronomical calendar in which seasons are defined by two solstices and two equinoxes. The Earth is tilted 23.5 degrees on its axis of rotation, and how the North Pole is oriented toward or away from the sun determines two of these astronomical dates. At the winter solstice in the Southern Hemisphere, the South Pole is tilted away from the sun, whereas at the summer solstice, the South Pole is tilted toward the sun. The equinoxes occur halfway between these events when the sun’s path is aligned with the Earth’s equator. The dates shown describe the astronomical seasons for the Southern Hemisphere in 2022; the exact dates vary slightly from year to year. Meteorological seasons are broken down into groupings of three months in our civil calendar based on the annual temperature cycle. We generally think of winter as the coldest time of the year and summer as the warmest time of the year, with spring and fall being the transition seasons. (NOAA Office of Education/Kaleigh Ballantine)

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Why do we have seasons?

The Earth is tilted 23.5 degrees on its axis, which affects the distribution of the sun’s energy across the surface of the planet. As the Earth orbits the sun every 365 ¼ days, the axis is always pointing in the same direction into space, with the North Pole toward Polaris, the North Star. Around June 22, the Northern Hemisphere is angled towards the sun, and receives the most direct radiation and the most energy. This is the start of astronomical summer in the Northern Hemisphere and winter in the Southern Hemisphere.

Six months later, in December, the Earth has completed half a revolution around the sun. The Northern Hemisphere is now angled away from the sun and receives less energy than the Southern Hemisphere; this is the beginning of winter in the Northern Hemisphere and summer in the Southern Hemisphere. From north to south, the results of the distribution of solar energy can be seen in changing vegetation, animal behaviors, temperatures, and day length.

Meteorological versus astronomical seasons

You may have noticed that meteorologists and climatologists define seasons differently from “regular” or astronomical spring, summer, fall, and winter.

Astronomical and meteorological seasons

Meteorologists and climatologists use a slightly different time scale for meteorological seasons than for astronomical winter, spring, summer, and fall. Why do meteorological and astronomical seasons begin and end on different dates? In short, it’s because the astronomical seasons are based on the position of the Earth in relation to the sun, whereas the meteorological seasons are based on the annual temperature cycle and help scientists track climate and weather trends.

Spring into science

Celebrate the season of spring with NOAA! From new graphics to educational resources, spring into science with us and check out our content.

Seasonal effects

Seasonal changes in precipitation and temperature affect soil moisture, evaporation rates, river flows, lake levels, and snow cover. Leaves fall and plants wither as cold and dry seasons approach.

These changes in vegetation affect the type and amount of food available for humans and other organisms. Animals in temperate and polar regions must find alternate food sources, move to warmer locations, or hibernate.

Beyond the big four

Though in the United States, we often think of the seasons as winter, spring, summer, and fall, but there are many different ways seasons change throughout the world, and even within the United States. Can you think of other annual climate events or ways to define seasons?

Groundhog Day forecasts and climate history

Even though he’s been forecasting since 1887, Punxsutawney Phil’s track record for the entire country isn’t perfect. To determine just how accurate he is, we’ve compared U.S. national temperatures with Phil’s forecasts. On average, Phil has gotten it right 40% of the time over the past 10 years.

EDUCATION CONNECTION

What are some ways that animals adapt to seasonal changes in your region? How does this compare to other areas? How do people adjust to the seasonal changes in their region? How do the seasons impact the use of energy in your community? The resources in this collection help educators encourage their students connect their own observations of the seasons to concepts in Earth science and biology.

The Changing of the Seasons of Life

Summer…a time of warmth and light. Of slow, steady growth.

Autumn…a time of change and preparation. Of looking towards what lies ahead while celebrating what has past.

Winter…a time of beauty in hardship. Of holding steady and hibernation.

Spring…a time of rapid growth. The turning of the tide from dormancy to life when everything bursts out in bloom.

Seasons of the year. Seasons in which nature flourishes and grows, changes colors and prepares for the coming cold, hibernates and waits patiently, then bursts forth with new growth and new life.

Have you ever really thought about the changing of the seasons? Or is it just one of those things that happens? Or has it become an annoyance because you have to change out all of your clothes and your children’s clothes so that they’re not wearing shorts in winter? Is it something that you look forward to? Or is it something you dread?

But what if we leave the clothes and closets and boots and flip flips alone for a minute?

What if we take a moment to consider how, just like the earth has seasons, our lives go through seasons?

Oh, the seasons of life are, sadly, not as predictable as the earth’s seasons! Sometimes they last a long time – sometimes a great deal longer than you want them to! Sometimes they last a short amount of time. Some years you may be in only one season while other years you may go through many, many seasons.

But that’s where the beauty lies: Each season is different. Each season will bring its own unique set of challenges, blessings, and opportunities. Each season will reveal more of your character as you allow it to refine you and shape you. You cannot control the seasons that come into your life (much as you may want to!), but you can control how you respond to each one. When you walk into a season with an attitude of learning and growing, there’s no end to what you can learn and accomplish in that season.

And yet when you talk about seasons in a big clump like this – all four seasons put together – sometimes it can start to get confusing. And, let’s face it: Life is confusing enough as it is! Let’s see if we can break this down a bit more:

Summer

Summertime and the livin’ is easy…
Summertime by Benjamin Green

Summer seems like a season where things almost go on autopilot. The intense growth of springtime is over. For the farmers, the planting season is complete and there’s this moment, this window of time to catch your breath. A time to sit back and enjoy. A time to almost rest. A time where you finally have that pattern figured out and it’s actually working for you and your family! A time to enjoy that tall glass of sweet tea on the rocking chair on the front porch while you listen to the drone of the katydids in the trees.

If you think about it, nature responds this way, too. Summer is a season of growth, no doubt – just look at the flowers and the farmer’s fields! – but at the same time, summer is not a season of explosive growth. It is a slow, steady, almost unnoticeable growth. It’s almost like nature is taking a break from the hustle and bustle of spring. Still growing, still moving forward, but taking things at a slower pace because everything is working and heading in the right direction.

Isn’t this so true of life? Have you entered those lovely summer seasons where that pattern you’ve been trying so hard to find finally clicks? That goal you’ve been working towards is finally achieved? That personality conflict you’ve been working through with a friend or your spouse finally melds together in a beautiful understanding? That place where everything just seems to fall into place and you have this moment to take a deep breath and enjoy this beautiful season of life.

All too often it feels like summer is fleeting, doesn’t it? Both in the physical seasons of the year and in life’s seasons! If you find yourself in this season of summer, embrace it! Enjoy it! Know that these beautiful, smoother, slower summer seasons don’t always last, but don’t let the fear of what might be coming taint this current season you’re in. Instead, approach it with a healthy dose of reality: Know that this season won’t last forever, but enjoy every moment of this lovely season while you can!

Autumn

There is something incredibly nostalgic and significant about the annual cascade of autumn leaves.
Joe L. Wheeler

Some people say autumn is a season of everything dying and it’s depressing. I disagree! Autumn is a season of change, a season of preparing, a season of eager anticipation for the incredible changes that are coming. Autumn is a time of brilliance. A time of rich harvest. A time of rich smells, spices, and tastes. A time of pumpkins and apples, a time of warming by the fire at night and basking in the sun during the day. A time of contrasts and brilliant colors everywhere you look.

Do you see those seasons in your life? Do you see the times of preparing? The times of knowing change is coming? The times where it feels like there’s a bit of urgency in the preparation, yet the knowledge that the preparation will be well worth it in the end? Do you feel the bounty of the harvest in your life? That feeling when a lesson really takes root and you start to see the benefit, the harvest of what you went through to learn this lesson? Do you feel the times of richness and abundance? There is a gratefulness in this season. Yet, there is a tension between looking back and the gratitude for everything you have walked through before and the anticipation for what’s coming next, looking forward to what lies ahead.

Sometimes in these autumn seasons, it becomes very easy to keep looking forward and to start getting anxious or scared about what is coming. It’s almost that feeling of waiting for the other shoe to drop and not knowing when it will come, right?

But in this season of abundance, don’t allow yourself to get so focused on the future that you forget the past. Take time to be grateful for the things that have brought you to this point. As cliche as it sounds, count your blessings. Even as you look towards the future, don’t forget to look back, remembering where you were, and celebrating where you are now and the lessons you learned to bring you to this point.

Winter

Embrace the seasons and cycles of your life. There is magic in change.
Bonnie Ware

To some, winter is bland and boring. I say it’s all in the way you look at it. Oh sure, on the outside it may look like the trees are doing nothing: just standing there with no leaves on them and waiting for the snow to fall. But on the inside, there is strength that can only be found by weathering the winter. On the inside, the sap still lives in the trees. It may have slowed down, but it’s still there! On the outside, the harsh and the cold of the weather and the snow may seem to have won. But on the inside there is a hardiness, a perseverance that can only be shown through the trials. The snow looks beautiful! Yet, despite its beauty, it has the ability to nourish and strengthen or it has the ability to break down and make brittle.

This is so true in life, isn’t it? Those winter seasons seem long and hard and cold. Sometimes it feels like there is no end in sight. Sometimes it seems the trials you are going through might break you altogether! But inside, inside is being forged a strength, a courage you would never have known you had unless you went through the trial of the winter. There are beautiful lessons to be learned in the winter seasons. Lessons of perseverance, lessons of strength. They may not be outwardly seen, yet these lessons of inner beauty and inner strength are being forged deep within you. Yes, sometimes the winter can be long and hard. Yes, the winter can be harsh and feel like it has won. But when spring bursts forth, the beauty that was refined in the winter is undeniable!

So often when you find yourself in a winter season, the temptation is to keep looking forward, isn’t it? To almost count down the days until this season is over and you can start on the next one. But here’s the thing about seasons of life: You never know how long or how short they’ll be! So, trying to count the days or simply “pull yourself up by your bootstraps” to make it through suddenly doesn’t feel like the best strategy, does it?

But what do you do? Sure, the lessons learned in winter are amazing, but how do you make it through the winter seasons in the first place? I wish there was an easy answer or a “miracle pill” I could hand you to make it all better, but the reality of it is this: Winter seasons are weathered one day at a time. And yet, there are three words that stand out as guiding beacons in these seasons: Hope, Perspective, and Perseverance.

Hope is essential because it reminds you that you are a part of something bigger than yourself. It gives you something to lean into. It reminds you that winter doesn’t last forever and springtime does come. Lean into your faith, press into the hope that is found in knowing the One who is in control and knowing that, no matter how hard the winter is, the spring does come.

Perspective is powerful because it allows you to lift your eyes from the situations and circumstances right in front of you and see that this season is not forever. It feeds your hope that lessons will be learned and that spring will come. Perspective gives you strength and the desire to keep going and keep persevering through the tough seasons.

Perseverance is the will and the drive to keep going, To keep taking one small step in the right direction. To keep going even when the going gets tough. To make the choice to do the next right thing and take the next step. Perseverance is tough! It can be draining. But when you reach the changing of the seasons and spring bursts into bloom in your life, you will see how your perseverance has paid off!

Spring

It’s a new season. A perfect opportunity to do something new, something bold, something beautiful!
Anonymous

Spring. The season where plants spring from the ground and leaves burst from the trees. A time of new birth and explosive growth. Spring is a jump start growing season. A time of stretching. A time of renewal and newness. A time of planting. Some growth you see immediately in the spring, like in the leaves of the trees and the wildflowers springing from the ground. Other growth, you have to plant and wait patiently for it to mature in the ground before it begins coming up and continuing the slow, steady growth of summer. Continuing to grow and blossom before it’s fully ready to be harvested in the autumn. Spring is a season of moving from the cold of winter to the warmth the sun brings. It’s a season of renewal and fresh perspective.

It’s this way in life, as well! Spring is a time of refreshing and renewal. A time where you move from the deep, inner learning of winter to living in what you’ve learned. It’s a time where you can see and feel growth happening. Sometimes this growth is painful, but the results and the fruit are so worth the effort!

When the springtime seasons happen in your life, enjoy them! Spring is a time to be celebrated. A time to marvel at the changes taking place in your life and in the lives of the people around you. It is a time of high energy and sometimes a lot of action! But in the action, in the commotion, in the excitement, don’t forget to take time to rest. Savor the moments as they happen. Live in the moment, absolutely! Enjoy them for all they’re worth! But take time to appreciate all the growth and the new life and the blooming that is happening.

You see, when the different seasons of life come (and they will!) these memories of spring, the reminder of the joy and the fullness of growth will give you motivation to keep going. These memories remind you that no matter which season of life you’re in now, spring does come.

What about you?

My Friend, what season are you in right now? Are you in summer? Winter? Are you in spring? Or maybe you’re in autumn? Each season looks different for each person. Each season comes with its own unique set of challenges and blessings. Each autumn of your life will look a little different than the other autumns in your life. Each season is unique all to itself and no two seasons will look exactly the same.

Where do you find yourself? Do you find yourself hating the season you’re in? Longing for it to be over so that you can move on? Can I offer you a word of encouragement? Don’t hate the seasons of your life. Now, I’m not saying all seasons will be filled with sunshine, flowers, and rainbows! Some seasons are harder than you ever imagined they could be! And yet, your mindset is so key to the experience you will have in this season of your life right now. Don’t hate the season. Don’t simply try to get through it and get on with life. Slow down. Start to change your mindset and look a this hard time as a season, a learning experience, not a time to simply endure and get behind you.

The key is to embrace your current season. To learn all you can from what is happening right here and right now. To lift up your eyes and see the beauty that is all around you if only you have the vision to see it.

Additional Resources:

Finding Perspective When You Feel You Have None
Improve Your Focus with Purpose: Lessons from Sunflowers
The Powerful Integration of Life and Music
Motivation to Keep Moving When Life is Hard

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Astronomical seasons

The four astronomical seasons that make up the year: spring, summer, autumn and winter begin when the center of the Sun passes one of the points on the ecliptic: the spring and autumn equinoxes, winter and summer solstices.

The main reason for the change of seasons is the tilt of the axis of our planet in relation to the plane of the ecliptic, that is, the plane of rotation of the Earth around the Sun. The Earth's axis is tilted from the plane of the ecliptic by 23.44 degrees. If this angle were equal to zero, the seasons would never change on the planet, the length of day and night would be the same, and the Sun would rise above the horizon to the same height throughout the year.

The change of seasons is not only on Earth. Consider the planets of the solar system.

The nearest planets to the Sun, Mercury and Venus, are not suitable examples, since these planets have almost no inclination of the axis of rotation to the ecliptic. Mercury is 0.01 degrees, and Venus is 177 degrees (it is upside down), which can be equated to 3 degrees.

Mars is similar to our planet in many ways. The inclination of the axis of rotation of Mars relative to the plane of its orbit is 25.2 degrees, which is only slightly more than the earth. Seasonality is similar to Earth, but a little more pronounced. When observed at different times of the year, you can see how the Martian “caps” at the poles change, melting occurs.

Jupiter's axis of rotation is tilted only 3 degrees with respect to the plane of the orbit. On the gas giant, the climate is not seasonal and is constant throughout the year.

The tilt of Saturn's axis of rotation is 29 degrees, so the change of seasons on this planet is characterized by more pronounced changes in the amount of sunlight than on Earth, and, consequently, temperature. All four seasons on Saturn last approximately 7 years. Since the entire year of the ringed planet lasts 29earth years. Depending on the time of year, Saturn can change its color. In the year when the automatic interplanetary station "Cassini" first approached the planet, it was winter in the northern hemisphere and this part of Saturn had a blue tint. Now it is summer in the northern hemisphere. This phenomenon occurs due to the intensity of ultraviolet radiation, in winter it decreases, in summer it rises. Well, the most noticeable fact of the change of seasons on Saturn is, of course, its rings. It is they who, for an observer from Earth, will quickly answer the question: “What season is it now on Saturn?” The inclination varies depending on the time of year, since the rings lie in the plane of the planet's equator, which means they have an inclination to the ecliptic equal to 29degrees. When it is summer in the northern hemisphere, the planet turns the northern hemisphere and its rings towards the Sun, and therefore towards the Earth, when it is winter, we see the southern hemisphere. During spring and autumn, the rings become so narrow for the observer that it is difficult to see them. At the equinoxes, Saturn turns into a planet without rings. They disappear.

The angle of inclination of the axis of rotation of Uranus is 97.86 degrees - it lies on its side, so the planet has a specific change of seasons, not similar to our planet.

On Neptune, the axis of rotation is deviated by 30 degrees, so the change of seasons here is similar to Earth, but the distance of the planet to the Sun makes its own adjustments. A year on Neptune is almost 165 Earth years, and each season lasts 41 years. Summer began in 2005 in the southern hemisphere and will last until 2046.

Does the sun always rise in the same place? No. With the change of seasons, the direction to the point of sunrise also changes. On the winter solstice, the sunrise and sunset points are closest to the south direction, and on the summer solstice they are closest to the north.

Days of equinoxes and solstices

Astronomical spring has arrived on March 20, 2020 at 10:49 local time. At this moment, the center of the solar disk will cross the celestial equator and move from the southern celestial hemisphere to the northern one. The height of the Sun on the celestial sphere and, accordingly, the daylight hours will increase until the onset of astronomical summer. This day is called the spring equinox. The fact that the equinox came so early is not surprising - it was a leap year.

June 21, 2020 at 4 hours 44 minutes - astronomical summer. The sun, moving along its path, will move as far as possible from the celestial equator and reach the northernmost point. This day is called the solstice.

September 22, 2020 at 20:31 - astronomical autumn. The sun on this day, moving along its path in the celestial sphere, crosses the equator and passes from the northern hemisphere to the southern. This day is called the autumnal equinox: day equals night. After that, the night in the northern hemisphere of the Earth becomes longer than the day, and in the southern hemisphere of the Earth the nights become shorter. This astronomical season will continue until December 21st.

The days around the autumnal equinox are favorable for astronomers and astronomers. The long night and relatively warm weather make it possible to carry out astronomical observations comfortably from evening to morning, about 12 o'clock.

During the equinoxes, the terminator on Earth - the line separating the day and night sides of the planet - is vertical and connects the north and south poles. This can be seen in the photographs of our planet, which are made by artificial satellites.

December 21, 2020 at 17 hours 2 minutes - winter solstice. The sun, moving along its path, will move as far as possible from the celestial equator and reach the southernmost point. The northern hemisphere has the shortest day, while the southern hemisphere has the longest. This is the most favorable period for observing various celestial objects in the night sky, but winter cold and frequent inclement weather (in central Russia) do not allow full-fledged observations.

The material was prepared by Victoria Damm, UC Planetarium
Sources: astronomical calendar for the 2019/2020 academic year. Issue 70;
Stellarium program.

Why the seasons change | First day of summer | When spring begins

If you have ever wondered why the seasons change on Earth, our article will be useful to you. We will talk about what approaches exist to determine the seasons, and also explain why the seasons succeed each other.

How many seasons are there in a year?
When are the seasons?
Why does the seasons change on Earth?
How do the seasons differ in different hemispheres?
Are there seasons on other planets?

How many seasons are there in a year?

Season or season is a period of the year characterized by certain weather conditions, average daily temperature and length of daylight hours. The number of seasons in a year depends on your geographical location and the cultural characteristics of your region. In temperate and circumpolar regions, 9 are usually distinguished0066 four seasons : spring, summer, autumn and winter.

In some South Asian countries, the year is divided into six seasons instead of four. For example, the Indian calendar has the following seasons: spring, summer, rainy season, autumn, early winter and late winter. In many tropical regions, there are only two seasons : the rainy season and the dry season.

When are the seasons?

There are two main approaches to determining the time limits of the seasons: meteorological and astronomical.

According to the meteorological approach, each season consists of three months and starts on the first day of the first month. Thus, in the Northern Hemisphere, meteorological spring begins on the first of March, summer on the first of June, autumn on the first of September, and winter on the first of December.

According to the astronomical approach, each season begins either on the day of the solstice (when the Sun reaches its northernmost or southernmost point in the sky) or on the day of the equinox (when the Sun crosses the celestial equator). In the Northern Hemisphere, the beginning of astronomical spring is counted from the March equinox, the beginning of summer - from the June solstice, the beginning of autumn - from the September equinox, and the beginning of winter - from the December solstice. Due to leap years, the dates of the equinoxes and solstices may differ by one or two days each year.

Why does the seasons change on Earth?

Many people think that the seasons change each other because of the ellipticity of the orbit of our planet: when the Earth approaches the Sun, it becomes warmer, and when it moves away, it becomes colder. However, the Earth's orbit is almost circular and does not significantly affect the weather and temperature conditions.

The main reason for the change of seasons is the tilt of the earth's axis . The axis of rotation of our planet is tilted at an angle of about 23.5 degrees with respect to the orbital plane. Most likely, the axis of rotation tilted after the collision of the Earth with another planet about the size of Mars.

Although the tilt of the axis of rotation remains unchanged, the orientation of the Earth relative to the Sun is constantly changing as the Earth revolves around the star. When one of the hemispheres of the Earth is turned towards the Sun, spring and summer come in this hemisphere; the other hemisphere at that moment receives less sunlight, and autumn and winter come there.

How do the seasons differ in different hemispheres?

The seasons in the northern and southern hemispheres are opposite. When it is winter in North America, it is summer in South America; when spring comes to Europe, autumn comes to Australia. As you now know, this is due to the fact that the Northern and Southern Hemispheres face the Sun at different times of the year.

Are there seasons on other planets?

The change of seasons is present on all the planets of the solar system, as their rotation axes are tilted. However, the seasons on other planets are different from those on Earth.