This article presents the project that is being carried out in the Climatology Department of the Servei Meteorològic de Catalunya (Meteorological Service of Catalonia), which aims to create a climatic database for Catalonia that is as complete and of the highest quality possible. Due to historical events, this climatic information is still incomplete and widely scattered in many different sources. As a consequence, it has been necessary to make a previous identification and cataloguing of the sources containing climatic material. Later on, a methodology used to integrate such a volume of information in a database was created, taking two aspects into consideration: the recovery of the metadata and the generation of climatic series. METADEM was developed to preserve all the information related to the metadata of a meteorological observatory, while a methodology was also designed to create complete and high quality climatic series. This one includes three levels: digitalization, quality control and homogeneity analysis. As a result of this project, which is still in its initial phase, ca. two hundred series have had their temporary coverage improved, while ca. one hundred and fifty new series have been identified.