1. Introduction. 2. Conditions of use and distribution. 3. Data storage and set up. 4. Installation and system set-up. 5. Using climate from cropwat. 6. Retrieval of climwat data. 7. Selection of climatic stations 8. Calculation procedures of climwat. 8.1 References evapotranspiration . 8.2 Mean relative humidity. 8.3 Windspeed. 8.4 Solar radiation. 8.5 Effective rainfall. 9. Example calculations.