 Weather forecasting is the application of science and technology to predict the state of the atmosphere for a given location . Human beings have attempted to predict the weather informally for millennia , and formally since the nineteenth century . Weather forecasts are made by collecting quantitative data about the current state of the atmosphere at a given place and using scientific understanding of atmospheric processes to project how the atmosphere will evolve . Since the early twentys , significant efforts have been made toward understanding and predicting and predicting larger-scale weather patterns. sierpniu 2018 , the World Meteorological Organization defined a weather forecast as containing at least ten or