The experimental campaign “Determination of the sources of atmospheric Aerosols in Urban and RuralEnvironments in Spain “(DAURE) took place in a urban (Barcelona city) and a rural (the Montseny Natural Park) Spanish sites. Its main objective was to study the formation and transport processes of particulate matter in the region during winter and summer time. This paper presents a description of the meteorological conditions during the campaign by means of meteorological observations, high-resolution mesoscale meteorological modelling and backward Lagrangian particle dispersion simulations. Modelling results are in agreement with observations and provide a valuable tool for characterizing transport patterns in relation to episodes of air pollution. An objective classification of the synoptic conditions and a classification of the main local dispersion patterns is presented and discussed. Additionally, themeasured PM1 and PM10 levels in both urban and rural sites are discussed and related to the meteorological conditions observed.