The study of analysis of rainfall is vital to find the relevant distribution model to anticipate the natural phenomena (earthquake, floods, rainfall, etc.;). The main theme of this study to determine the best fit of probability distribution in the case of frequency of daily rainfall in past 37 years (1982- 2019) from all districts of the state of Andhra Pradesh, India, by using different statistical analysis and continuous probability distributions. The daily rainfall data are analysed using two different probability models, those are Double Exponential Distribution and Log-Pearson III Probability Distribution. Efficiency of the all probability models are compared using Root Mean Squared Error (RMSE) value of Chi-square Goodness of Fit. It is precisely witnessed that the Double Exponential Distribution was identified to be the best fit for forecasting daily rainfall (mm).