Late blight of potato caused by Phytophthora infestans (Mont.) de Bary, is one of the most serious and devastating disease of potato world over, including India and is an important limiting factor for yield reduction in India. Management of potato late blight has always been a challenge for both scientists as well as growers. For effective management of disease, efforts should made to reduce initial inoculum (in temperate conditions) but main emphasis should be to slow down progress of disease. Hence, there is urgent need to develop some kind of disease forecast/warning service for predicting the time of appearance of disease and optimizing use of fungicides without risking the crop and human health. A disease forecasting model predicts out-break or changes in intensity of one or more diseases on the basis of information about weather, crop, pathogen(s) or some combination of the three. Various forecasting models have been developed and utilized over the years for predicting late blight of potato across the globe. Based on four weather parameters, viz. dew points, night temperature, cloudiness and rainfall to predict initial appearance of late blight in Holland. But such models are not universal in adoption but have impetus for several workers. The implementation of forecasting model for late blight of potato depends upon area specific climatic conditions.