For most people , the word weather means the sun ,rain , wind or snow . if you live in southern Europe or Africa , you know the temperatures are higher and there is less rain than if you live in northern Europe or Canada.
However , strange weather can occur all over the world. For example , people have seen giant pieces of ice falling from the sky.
And what would you think if you saw a ball of light as big as football. Weather experts call these balls lightning.

Some storms are very unusual and may cause terrible damage .
The English town of Dunwich was once an important port , but in the fourteen century , high waves and violent storms hit the area and most of the town disappeared beneath the sea .
The worst storm in Britain killed more than 8000 people in 1703 .
The worst flood in the history was in 1887 in china when yellow river flooded and killed around a million people .

Unusual weather is becoming more common , with very high or low Temperatures and very heavy rainfall all over the world .
this causes serious droughts in some places and floods in others .
However , this is not modern phenomenon : in Europe in eighteenth century , there was a little ice age when rivers like River Thames in England froze .
What will happen to our weather in the future ? no one knows , but one day " unusual " weather may not be unusual anymore .