passage: The Earth is tilted 23 1/2 on its axis .
  This means that as the Earth rotates , one hemisphere has longer days with shorter nights .
  At the same time the other hemisphere has shorter days and longer nights .
  For example , in the Northern hemisphere summer begins on June 21 .
  On this date , the North Pole is pointed directly toward the Sun .
  This is the longest day and shortest night of the year in the Northern Hemisphere .
  The South Pole is pointed The hemisphere that is tilted away from the Sun is cooler because it receives fewer direct rays .
  As Earth orbits the Sun , the Northern Hemisphere goes from winter to spring , then summer and fall .
  The Southern Hemisphere does the opposite from summer to fall to winter to spring .
  When it is winter in the Northern hemisphere , it is summer in the Southern hemisphere , and vice versa .
  What does this mean for you ?
  If you live in North America , July 1 is usually a very warm day .
  If you traveled to Southern Australia , you would need a heavy coat .
  At the equator , the seasons never change .
  As a result , the average daily temperatures remain the same .
  There is no summer and winter as we know them .
query_and_answer: What happens on June 21 in the Northern Hemisphere ? || it is summer
evidences: On this date , the North Pole is pointed directly toward the Sun . This is the longest day and shortest night of the year in the Northern Hemisphere .