Climatic and geographical variables are known to be important in determining the risk of fluke infection, because of their effect on the survival and rate of development of the parasite on pasture and in the intermediate host, Galba truncatula, and on the intermediate host itself. A predictive model based on climate data first developed by Ollerenshaw and Rowlands (1959) is still used on the National Animal Disease Information Service (NADIS) website to predict years when fluke infection related losses will be heaviest, enabling farmers to plan ahead (NADIS, 2014). More recent work on climate showed that geographical and climate variables can explain 70–76% of variation in fluke infection at the level of postcode area (McCann et al., 2010a)