The paper presents a software architecture based on open source technologies, implemented by the authors in an experience of processing spatio-temporal data gathered by rain gauges spread across two regions of central Italy. The interest in the automatic processing of data about precipitation is widespread, however, today only an inner circle of stakeholders can think of taking advantage of the available open source libraries because a strong programming skill is required to use them. It is opinion of the authors that the implemented software architecture is suitable for expanding the community of users able to process “by themselves” historical precipitation data. The centre of the architecture is the technology of the spatial database management systems. They offer full support for the creation and management of a spatial database suitable to store the rainfall data usually spread out in several files. Moreover, they allow adding to such a repository a large set of ad hoc “objects” oriented to carrying out spatio-temporal computations on the precipitation. The stakeholders are only required to familiarize with the database’s objects and invoke their execution. A large part of the paper is devoted to show how the adopted conceptual setting can assist nontechnical users in carrying out personalized computations on rain gauges data. The computing needs posed by the experience described in this paper are common to many other areas of high social impact that involve spatio-temporal data, hence we believe that the implemented framework can be exported to them, keeping unaltered operational effectiveness.