Weather conditions that are humid and rainy or cold and dry appear to promote influenza transmission, report researchers from the National Institutes of Health Fogarty International Center.
The researchers examined the relationship between climate factors and influenza epidemics at a globally representative sample of 78 sites (Tamerius JD et al. PLoS Pathog. 2012;9:e1003194). They found that in northern regions of the world, influenza peaks about a month after a period when humidity and temperatures are very low. The authors note that previous studies suggested that flu viruses may survive better and spread more easily when conditions are dry.
Kuehn BM. Flu and Climate. JAMA. 2013;309(16):1674. doi:10.1001/jama.2013.4245