Introduction: The purpose of this article is to report the main findings of a retrospective study (1995–2010) on the influence of meteorological factors on peaks in nuisance caused by Aedes caspius bites in Nantes, and to describe the nuisance observed between 2011 and 2013. Methods: Four sources of information were used: insect bite diagnoses made by SOS Médecins Nantes, mosquito egg hatching dates recorded by the Interdepartmental Agency for Mosquito Control on the Atlantic Coast in the Loire Estuary, meteorological data provided by Météo-France, and tidal coefficients from the Port of Saint-Nazaire. The Cusum method was used to determine periods of peak nuisance. Results: From 1995 to 2010, seven periods of peak nuisance related to bites were identified. Two factors contributed to these nuisance events: very high-intensity tides (threshold of 108) and prevailing westerly winds during the second week following an outbreak. Between 2011 and 2013, a period of peak nuisance activity resulting from the combination of these two factors was observed in 2013. Discussion-Conclusion: The prospective monitoring of meteorological data and diagnoses made by SOS Médecins, implemented since 2011, has validated the factors favoring the outbreak and movement of Ae. caspius in the Loire estuary identified in the study. (R.A.)