This book essentially comprises the proceedings of the 11th International Conference of Meteorology, Climatology and Atmospheric Physics (COMECAP 2012) that is held in Athens from 30 May to 1 June 2012. The Conference addresses researchers, professionals and students interested in the following topics: Agricultural Meteorology and Climatology, Air Quality, Applied Meteorology and Climatology, Applications of Meteorology in the Energy Sector, Atmospheric Physics and Chemistry, Atmospheric Radiation, Atmospheric Boundary Layer, Biometeorology and Bioclimatology, Climate Dynamics, Climatic Changes, Cloud Physics, Dynamic and Synoptic Μeteorology, Extreme Events, Hydrology and Hydrometeorology, Mesoscale Meteorology, Micrometeorology/Urban Microclimate, Remote Sensing/ Satellite Meteorology and Climatology, Weather Analysis and Forecasting. The book includes all papers that have been accepted for presentation at the conference.