This dataset collection contains datasets of 5 day back trajectories have been computed on a routine basis using analyses from the European Centre for Medium Range Weather Forecasting (ECMWF). The three components of the wind and surface pressure over three launch grids covering the UK, the mid-Atlantic storm track region and the eastern USA, plus back trajectories from field campaign instrument sites were used to output datasets consisting of latitude, longitude and pressure of the trajectory every 30 minutes.