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    Why is it hot in summer and cold in winter?


    Because the earth's axis is tilted.

It is all about the tilt of the Earth's axis. Many people believe that the temperature changes because the Earth is closer to the sun in summer and farther from the sun in winter. In fact, the Earth is farthest from the sun in July and is closest to the sun in January!

During the summer, the sun's rays hit the Earth at a steep angle. The light does not spread out as much, thus increasing the amount of energy hitting any given spot. Also, the long daylight hours allow the Earth plenty of time to reach warm temperatures.

During the winter, the sun's rays hit the Earth at a shallow angle. These rays are more spread out, which minimizes the amount of energy that hits any given spot. Also, the long nights and short days prevent the Earth from warming up. Thus, we have winter!


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Library of Congress Web SiteFurther Reading
  • Asimov, Isaac. Isaac Asimov’s guide to earth and space. New York, Random House. 1991. 285 p. (Questions and Answers).
  • Campbell, Ann-Jeanette. The New York Public Library incredible Earth: a book of answers for kids. New York, Wiley, c.1996. 186 p.
  • Gutsch, William A. Jr. 1001 Things everyone should know about the universe. New York, Doubleday,1998. 353 p.
  • Thompson, Luke. Earth. New York, PowerKids Press, 2001. 24 p. (Juvenile).
  • Pasachoff, Jay. Astronomy: from the earth to the universe, 6th edition. United States, Brooks/ Cole- Thompson Learning, c. 2002. 1v. various

SearchFor more print resources...
Search on "astronomy," "earth," "seasons," "summer," "summer solstice," "weather," "winter," or "winter solstice. in the Library of Congress Online Catalog.

Image: summer scene Summer
More hours of sun / daylight

The sun’s rays come in at a steeper angle, with fewer layers of atmosphere to filter through.

Image: winter scene Winter
Fewer hours of sun / daylight

The sun’s rays come in at a shallow angle with more atmosphere to filter through.


Photo: hills and buildings covered in snow.
Winter in Yellowstone National Park. From the National Park Service Web site..

Photo: trees with vivid red and gold leaves.
Fall colors at Blueberry Ridge, near the Weather Service office in Marquette, MI. From the National Weather Service Website.

Photo: young girl posing in the sand on the beach.
"It's fun at Long Beach, Aug. 9, 1919." From Prints & Photographs Division, Library of Congress.

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 September 26, 2018
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