The Federal Office of Meteorology and Climatology MeteoSwiss is by federal mandate the national provider for weather and climate services in Switzerland. In this role, it serves the general public, authorities, research and industry. MeteoSwiss monitors the atmosphere over Switzerland and operates the corresponding networks, it issues weather forecasts, warns the authorities and the general public of dangerous weather conditions and also monitors the Swiss climate. The legal duties include the provision of climate information and climatological services for the benefit of the general public. MeteoSwiss provides generic and tailor-made datasets and services for customers, and conducts research on themes from weather and climate to high-performance computing. Weather and climate in the Alpine region is one of its core competences. MeteoSwiss hosts the national GCOS office and is the official representative of Switzerland in various international organisations (WMO, ECMWF, EUMETSAT, EUMETNET etc.) and member of the Swiss Centre for Climate Systems Modelling (C2SM). In its research MeteoSwiss collaborates with academia (e.g. ETH Zurich and Swiss National Supercomputing Centre CSCS), with other governmental offices (e.g. hydrology) and the private sector (e.g. reinsurance). In the framework of the Swiss HP2C and PASC Initiatives, MeteoSwiss has led the adaption of the regional weather and climate model (COSMO) to hybrid high-performance computing systems and has spearheaded the application of domain-specific languages in operational atmospheric codes. On the basis of its numerical weather forecasting models, MeteoSwiss has issued weather and climate forecasts to commercial customers for over ten years now and has also a profound experience in the communication of such forecasts to the public and media.