This paper assesses the radiometric performance of the Arctic Weather Satellite (AWS) with respect to the ECMWF data assimilation system and heritage sensors. The AWS is the first mission of the European Space Agency designed according to “NewSpace” principles. Its objective is to improve weather forecasting through a rapidly developed, low-cost mission. AWS also serves as a pathfinder for the recently approved Polar System (EPS) Sterna constellation, representing a paradigm shift in operational satellite meteorology. Despite its compact size, AWS has proven to be a high-performing radiometer, delivering data quality suitable for operational assimilation in numerical weather prediction, where it has been used operationally for nearly one year.