Attila Jaeger develops an application which notifies a vehicle's driver of upcoming road weather dangers. This application maps the information evaluated by in-vehicle sensors in order to draw conclusions on the current weather condition. Comprehensive data basis is gained by sharing information with other vehicles using Car-to-X communication. In order to prove usability of the presented approaches, the developed application and selected concepts are implemented and deployed within the context of large scale Car-to-X field operational trials simTD and DRIVE C2X. Car-to-X communication is considered as the next major step towards a significant increase in road safety and traffic efficiency.