In 2006, over 2000 cases of bluetongue were recorded in northern Europe. The disease, which has been more typically associated with Mediterranean areas, is believed to have become established hundreds of kilometres to the north of its traditional area, probably as a consequence of the hottest summer/autumn period since records began. In this special article, John Gloster and colleagues describe the meteorological conditions surrounding the 2006 outbreak, and investigate the possibility of bluetongue virus (btv) spreading on the wind to the uk in 2007. For this to happen there would need to be a source of windborne virus, together with a susceptible population of ruminants in the vicinity of the coast. Evidence from outbreaks in the Mediterranean Basin suggests that long-distance transport of btv-infected vectors has already occurred, at least in that region. The overall likelihood of this occurring in northern Europe depends critically on whether the virus overwinters on the near continent; this will not be known until around May 2007. The 2006 outbreak has highlighted the importance of understanding the impact of climate change on animal disease.