European health agencies have reported a record number of mosquito-borne disease outbreaks in 2025, marking a new phase of longer, more widespread, and intense transmission seasons across the continent. The European Centre for Disease Prevention and Control (ECDC) and other regional health authorities have highlighted outbreaks of diseases such as chikungunya, dengue fever, and West Nile virus, which were previously confined to tropical regions. This surge includes 27 chikungunya outbreaks, 335 West Nile virus cases, and 19 deaths. Climate change is identified as a key factor driving this increase, with rising temperatures, longer summers, milder winters, and altered rainfall patterns creating favorable conditions for mosquito populations. France has experienced a particularly notable rise in cases, described by health officials as an unprecedented and worrying situation. The World Health Organization's European office has also confirmed the expanding geographic range of these diseases beyond traditional tropical zones, signaling that mosquito-borne illnesses are becoming a new normal in Europe.