This work describes a mountain meteorological network that was in operation from 1999 to 2014 in a mountain range with elevations ranging from 1104 to 2428 m in Central Spain. Additionally, some technical details of the network are described, as well as variables measured and some meta information presented, which is expected to be useful for future users of the observational database. A strong emphasis is made on showing the observational methods and protocols evolution, as it will help researchers to understand the sources of errors, data gaps and the final stage of the network. This paper summarizes mostly the common sources of errors when designing and operating a small network of this kind, so it can be useful for individual researchers and small size groups that undertake a similar task on their own. Strengths and weaknesses of some of the variables measured are discussed and some basic calculations are made in order to show the potential of the database and to anticipate future deeper climatological analyses over the area. Finally, the configuration of an automatic mountain meteorology station is suggested as a result of the lessons learned and the the common state of the art automatic measuring techniques.

Abstract.Mountains have a very peculiar climate, are an essential factor in the climate system and are excellent areas for monitoring weather and climate. Nevertheless there is still a lack of long term observations at these areas, mainly due to their harsh conditions for instruments and humans. This work describes the results obtained in the design, installation and operation during more than a decade of a mountain meteorological network located in Sierra de Guadarrama (Iberian Central System, Spain). This work includes information about the measuring strategy, objectives and performance of the network with some technical and operational conlussions that might be useful for the mountain meteorology observation community. Discussions about the representativeness of the data are shown. These are important for future users of this data base. Also some basic statistics of the available data is shown as a framework for further and deeper analysis. Finally some recommendations are made about mountain meteorology observation which could be taken into account for future improvements of this network or for other mountain meteorological networks.