The south-west monsoon (June–September) is the major rainy season overIndia. Information about the occurrence of precipitation and the expectedquantity at a specific place is important in many sectors of humanactivity. In this study, objective methods are developed to forecastthe probability of precipitation (POP) and provide the quantity ofprecipitation forecast (QPF) over Delhi. As the onset of the monsoonat Delhi is around 30 June, the models are developed for the monthsof July, August and September (JAS) using surface and upper-air datafor the period 1985–90 and tested with data from JAS for 1994and 1995. A multiple linear regression equation is developed to forecastthe POP and multiple discriminant analysis is used to produce the QPF interms of one of four groups (0.1–1.0; 1.1–10.0;10.1–30.0; and ≥ 30.1 mm). The QPF model is used onlyif precipitation is expected to occur (the POP forecast is turnedinto a categorical forecast). The categorical forecasts based on the POPexhibit positive skill scores consistently with both the development andindependent data sets. The model for QPF also performed satisfactorily