seasons

• The passing of a year can bring a marked change in the weather and the surrounding environment. The four seasons — winter, spring, summer, autumn — can vary significantly in characteristics and can prompt changes in the world around them.
• Season


  Any of four divisions of the year according to consistent annual changes in the weather
• In the Northern Hemisphere, seasons are commonly regarded as beginning respectively on the winter solstice, December 21 or 22; on the vernal equinox, March 20 or 21; on the summer solstice, June 21 or 22; and on the autumnal equinox, September 22 or 23
• At the equinoxes, the days and nights are equal in length; at the winter solstice the day is the year's shortest, and at the summer solstice it is the year's longest
• In the Southern Hemisphere, summer and winter are reversed, as are spring and fall
• Characteristics of the seasons

  • In autumn the amount of time it is light becomes less, the leaves start to change color and fall off the trees
  • In winter we have colder weather, sometimes snow and frost, the trees have no leaves and the amount of time it is light during the day is at its shortest
  • In spring the weather usually turns warmer, trees begin to grow their leaves, plants start to flower and young animals such as chicks and lambs are born
  • In summer the weather is usually warm, trees have full green leaves, and the amount of time it is light for during the day is long
• Earth's tilted axis causes the seasons
• When the North Pole tilts toward the Sun, it's summer in the Northern Hemisphere. And when the South Pole tilts toward the Sun, it's winter in the Northern Hemisphere
• Earth's orbit is not a perfect circle. It is a bit lop-sided. During part of the year, Earth is closer to the sun than at other times
• Compared with how far away the sun is, this change in Earth's distance throughout the year does not make much difference to our weather
• Long, long ago, when Earth was young, it is thought that something big hit Earth and knocked it off-kilter. That big thing that hit Earth is called Theia
• As Earth orbits the sun, its tilted axis always points in the same direction. So, throughout the year, different parts of Earth get the sun's direct rays
• The added hours of daylight are one reason why summer is warmer than winter. But there's another reason that's even more important: the angle of the mid-day sun
• The sun's rays strike the ground more directly in June. In December, on the other hand, the same amount of energy is diluted over a larger area of ground

  
• The sun happens to be closest to us in January