CHIKV is indigenous to tropical Africa and Asia. WNV was first found in a tropical region in Africa, and has since been described in Africa, Southern Europe, the Middle East, west and central Asia, Oceania and North America. Northward migration and increasing numbers of air transports, combined with the ability of the mosquitoes to adapt to different ecological situations is allowing for the introduction of these mosquito species in larger parts of Europe. Climate scenarios for the near future predict that many parts of Europe will become warmer and more humid. These changes are likely to increase the risks of WNV and CHIKV outbreaks in these parts of Europe, because of vectors’ longer activity seasons, larger geographical areas becoming affected, and difficulties of eradicating the disease in Europe with an already established vector population.