Heatwaves Constrain the Future Persistence of Mosquito Vectors in Europe

Climate warming is intensifying heatwaves across Europe, but the upper thermal limits of arboviral mosquito vectors-and their implications for future distribution-remain poorly understood. Using experimentally derived life-stage-specific upper thermal limits, we identified the impact of heat extremes on the persistence of Culex pipiens, Aedes albopictus and Aedes aegypti in Europe under present and future climate scenarios (SSP126, SSP370 and SSP585). Our projections reveal that by 2100, large parts of southern Europe, including the Iberian Peninsula, will exceed the thermal limits for Cx. pipiens, with heat-limited zones expanding northward into central Europe. Aedes albopictus faces moderate future constraints, while Ae. aegypti remains largely unrestricted by extreme heat, though high mortality at low humidity may still limit its establishment in continental Europe. Divergent plasticity in heat tolerance among life-stages, species, their acclimation status and the interplay with humidity exposure underscore the complexity of thermal adaptation. This integrative experimental-modelling framework highlights when and where it may become too hot for Europe's major mosquito vectors, refining spatial risk forecasts for arbovirus emergence under climate change.