Germany's national meteorological service, the Deutscher Wetterdienst, provides both current weather and historic climate data on its open data server.
The purpose of this project is to process the provided historic precipitation data from 5579 individual weather stations. The data for each station is provided as a separate zip file, containing a number of csv files that represent a relational data structure. These data cam be combined to form a single relational database, allowing the full precipitation data to be analysed.
The script R/dwd-precip-R shows how a selection of files can be processed to form a combined, relational dataset.