The Reason for the Seasons

What Causes the Four Seasons?

December 17, 2020
Four Seasons

The four seasons in North America.


What causes our four seasons—winter, spring, summer, and fall? People puzzled over this for centuries. (Hint: It’s not the distance between the Sun and Earth.) Find the reasons for the seasons. 

In one year, Earth revolves completely around the Sun while rotating on an invisible axis, like a tilted, spinning top.

  • At one end of the axis is the North Pole; at the other, the South Pole.
  • The axis is tilted at a 23.5-degree angle away from the Sun during winter in the Northern Hemisphere; it’s the opposite during summer.

Seasons are determined by the direction of Earth’s tilt in relation to the Sun and the angle of the Sun’s light as it strikes Earth!


The equator is an imaginary line dividing Earth into the Northern and Southern Hemispheres.

  • On two days each year, on or around March 21 and September 23, the Sun is directly above the equator.  In the Northern Hemisphere, spring starts on the March date, which is called the vernal equinox; fall begins on the September date, which is called the autumnal equinox.
  • Summer in the Northern Hemisphere begins on or around June 21, the summer solstice, when the Sun is directly above an imaginary line 23.5 degrees north of the equator called the Tropic of Cancer.
  • Winter begins on or around December 21, the winter solstice, when the Sun is above the Tropic of Capricorn, 23.5 degrees south of the equator. The seasons are the opposite in the Southern Hemisphere.


The Long and Short of It

  • The summer solstice is one of the longest days of the year in the Northern Hemisphere—and the day when there is no sunlight at the South Pole. 
  • The winter solstice is one of the shortest days of the year in the Northern Hemisphere—and the day when there is no sunlight at the North Pole. 
  • Daytime and nighttime on the equinoxes are not equal; this is a myth. However, within a few days of each equinox, there is a day with nearly equal daytime and nighttime.  (This depends on the latitude.)

Find the dates for the solstices and equinoxes!


Celebrating the Changes of Season

For centuries, people have watched the sky for the changes of season and then celebrated with colorful rituals.

In India, many people celebrate the festival of Navroze, or “New Day,” on the spring equinox. It is a day to clean and paint houses, wear new clothes, and hang jasmine flowers and roses on doors and windows.

In ancient times, women and girls in Sweden would bathe in a river in the belief that this would bring plenty of rain for the crops, while village people would dance around a decorated tree. Now, in late June, Swedes dance around a pole covered with greenery and flowers.

The Chinese mark the end of summer with the Mid-Autumn Moon Festival, which occurs when the Moon is at its brightest. After dark, people stroll with brightly lit lanterns, admire the full Moon, and eat moon cakes, which are pastries with a whole egg yolk in the center symbolizing the Moon.

Ancient Romans welcomed winter with the festival of Saturnalia, honoring Saturn, the god of  agriculture. People decorated their houses with evergreen branches and lit lamps all night to ward off the darkness.

Around the time of the solstice, in ancient Scandinavia, people hung mistletoe and evergreens in doorways for good luck and then gathered around bonfires to listen to singing poets. They believed that the fires would help the Sun shine more brightly.


Ancient Sites Marking the Seasons

From ancient times through today, people visit monuments or markers that celebrate the relation between the Sun and the seasons. See five famous ancient seasonal markers.


The Old Farmer's Almanac for Kids, Volume 2


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i love this !!!!!!!!!!!!

i love this !!!!!!!!!!!!

I love this site! I was

I love this site! I was brought up in Georgia, I lived in Victoria, Canada for 10 years, and now I am living in Bellingham WA. Welcome to the WET coast. I spent many summer trips to my Grand-parents home in South Ga., and my grandmother swore by that almanac, it was their planting bible. This brings back many great memories of life on their farm...picking blackberries, helping grandfather pick vegs. out of the massive garden, smelling the aromas from my grandmothers' kitchen, learning how to prepare, and can vegs. The giant storage closet where all the vegs. were store on shelves. All the beautiful colors in the jars. Looked like a garden rainbow! I am going back to that type of living of the land soon. Can't take the country out of me!

Today (9/23/12) I stumbled

Today (9/23/12) I stumbled onto The Old Farmer's Almanac because I wanted to know the date fall started. Well, I'm thrilled because I love the Almanac + Yankee Mag, etc. So I registered. I look forward to your email--I don't facebook, twitter, twotter, whatever. eMail is enough for me.
Kate Starr
Rockport, MA

So nice to read of 'normal'

So nice to read of 'normal' people out there.
Welcome to 'my' world! E-mail is wonderful, and all one needs.