Look at images of medival times. Notice how the summers seemed
  brighter, the spring...times described in song and in tapestries
  seem warmer... they figured out that, in fact, it WAS warmer
  during that period of time. That's part of the reason why the
  bubonic plague spread so rapidly. The summers were practically
  tropical and hence the rapid spread and growth of diseases. The
  snowy cold we think of for england didn't come about 'til about
  the 1600's or so, a period we're still living in today. This is
  according to some... "