Data mining is a rapidly developing technology that has enriched a lot of field such as business analysis, market analysis, weather forecasting, stock market analysis and many more. It starts with collecting data sets from reliable sources and pre-processing that data. There are some anomalies associated with data collected in large volumes such as outliers, missing values, and duplicated values. Removal of these kind of anomalies is termed as pre-processing of data. In this paper, a rainfall prediction model has been proposed using decision tree and artificial neural network data mining techniques.