Research carried out by the Health Protection Agency has found that higher temperatures and increases in humidity are linked with an increase in cases. The findings showed that in warmer weather there were 551 reported cases and 52 deaths from legionnaires compared with 389 reported cases the previous year, which was cooler.

Kate Ricketts, a scientist specialising in Legionnaires' disease at the Agency's Centre for Infections explained that "The study suggests that the number of cases may be associated with the weather. It remains to be seen what impact the weather will have in the future. There may be important implications for public health authorities if climate change leads to warmer temperatures."