Why is weather so hard to predict accurately?

People rely on forecasts for everything from safely landing an aircraft to running an outdoor event, but it's actually very hard for weather forecasters to be 100 per cent accurate about what the weather is going to do. Why?

S4C weather forecast

Think about the weather where you live:

  • For how long does the weather stay the same?
  • If you go to a place, or phone a friend, 5 miles from your house is the weather the same there as at your home?
  • Watch the clouds on a windy day - do they all move in the same direction?
  • Why do you think weather is so variable?

Weather can change rapidly and often, so meteorologists speak about the chance of rain or sunshine in terms of percentages. They can never be absolutely sure of future weather events.

The accuracy of the measuring instruments and frequency of data gathering defines how accurate a forecast will be. Go to Where do weather forecasts come from? to find out how meteorologists measure the weather.

Weather Data Experiment

weather Schools across the UK can report local weather to help improve forecast
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