Precipitation is a very important environmental parameter that influences many aspects of our daily life. Most precipitation data sets currently available focus on local or regional scales. There are only few internet web sites that offer data sets that cover the globe. Most of these sites provide data for download only and few provides browse images which are often hard to read. Ordinary users have to download and process them in order to visualize and analyze them, which often creates a difficulty to the users due to the lack of the knowledge and the equipment.

With data from the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Change Project (GPCP), we are developing an online analysis and visualization interface to allow users to easily and quickly access precipitation information around the world. The interface will allow users to 1) selecting an area of interest and time interval; 2) obtain rainfall for the area; 3) conduct simple analyses, such as, area average and time series; 4) compute anomalies and conduct map differencing; and 5) download data in ASCII for their customized analyses or applications.